BENZENAMINE

Benzenamine is used a standard sample for measuring the refractive index.
Benzenamine is used halogen, chromate, vanadate, nitrite and carboxylic acid were detected.
Benzenamine is used for the pharmaceutical industry, organic synthesis.

CAS Number: 62-53-3
EC / EINECS Number: 200-539-3
Molecular Formula: C6H7N / C6H5NH2
Molecular Weight: ≈ 93.13 g/mol

SYNONYMS:
Aniline, Benzenamine, Phenylamine, Aminobenzene, Benzamine, Aminophen, Phenyl-NH₂, Anilin, Aniline oil, Cyanol, Blue oil, C.I. 76000, Aryl amine, Benze-Neamine, Amino-benzene, Aniline, Benzenamine, Phenylamine, Aminobenzene, Benzamine, benzamine, aniline oil, phenylamine, aminobenzene, aniline oil, phenylamine, aminophen, kyanol, benzidam, blue oil, C.I. 76000, C.I. oxidation base 1, cyanol, krystallin, anyvim, arylamine, ANILINE, Benzenamine, 62-53-3, Phenylamine, Aminobenzene, Aminophen, Kyanol, Arylamine, Anilin, Cyanol, Benzeneamine, Krystallin, Benzidam, Anyvim, Anilina, Benzene, amino, Huile D'aniline, C.I. Oxidation Base 1, Rcra waste number U012, CI Oxidation Base 1, Anilinum, C.I. 76000, HSDB 43, NCI-C03736, SIR7XX2F1K, EPA Pesticide Chemical Code 251400, CI 76000, DTXSID8020090, CHEBI:17296, DTXCID9090, RefChem:6616, 200-539-3, MFCD00007629, Aniline reagent, ANILINE-N,N-D2, UN 1547, Aniline-1-13C, Anilin [Czech], Caswell No. 051C, 62-53-3(methanol), Huile d'aniline [French], Phenyleneamine, D'aniline, RCRA waste no. U012, Anilina [Italian, Polish], CCRIS 44, 136260-71-4, Aniline and homologs, Aniline and homologues, EINECS 200-539-3, UNII-SIR7XX2F1K, UN1547, cyanole, BIDD:ER0581, phenyl amine, phenyl-amine, AI3-03053, Aniline solution, 8-aniline, Benzene, amino-, Aniline in methanol, Fentanyl impurity F, Aniline, Aminobenzene, PhNH2, Aniline, ACS Grade, ANILINUM [HPUS], ANILINE [HSDB], ANILINE [IARC], ANILINE [MI], ANILINE [MART.], Mesalazine EP Impurity K, ANILINE [USP-RS], ANILINE [WHO-DD], CHEMBL538, Epitope ID:117704, EC 200-539-3, SCHEMBL5207, Aniline, analytical standard, Aniline, AR, >=99%, Aniline, LR, >=99%, SCHEMBL11803, SCHEMBL20581, SCHEMBL22106, SCHEMBL41824, C6H5NH2, SCHEMBL128217, SCHEMBL464981, Discontinued, see H924510, ANILINE [USP IMPURITY], SCHEMBL1227384, SCHEMBL1681945, SCHEMBL2922010, SCHEMBL3050204, SCHEMBL4537658, SCHEMBL4622218, SCHEMBL7573764, SCHEMBL9231132, SCHEMBL9771553, Aniline, 99.5%, ACS grade, BDBM92572, Trimethoprim specified impurity K, Aniline, ReagentPlus(R), 99%, BENZENE,AMINO (ANILINE), MSK1225, Aniline [UN1547] [Poison], Aniline Solution, 1,000 mg/L, BAA12259, STR00216, Aniline (Mesalazine EP Impurity K), Aniline, ACS reagent, >=99.5%, Tox21_200345, Aniline 10 microg/mL in Cyclohexane, EBC-47536, STK301792, AKOS000268796, Aniline 100 microg/mL in Cyclohexane, DB06728, FA07686, Aniline, ASTM, ACS reagent, 99.5%, Aniline, SAJ first grade, >=99.0%, CAS-62-53-3, Aniline, JIS special grade, >=99.0%, Aniline, p.a., ACS reagent, 99.0%, NCGC00091297-01, NCGC00091297-02, NCGC00091297-03, NCGC00257899-01, BP-12047, FENTANYL IMPURITY F [EP IMPURITY], Aniline, PESTANAL(R), analytical standard, DB-013441, MESALAZINE IMPURITY K [EP IMPURITY], A0463, NS00010656, TRIMETHOPRIM IMPURITY K [EP IMPURITY], EN300-33390, C00292, SBI-0653858.0001, A833829, AMINOBENZOIC ACID IMPURITY C [EP IMPURITY], F044723, F989025, Q186414, SR-01000944923, SR-01000944923-1, Q27121173, F2190-0417, InChI=1/C6H7N/c7-6-4-2-1-3-5-6/h1-5H,7H, Aniline, United States Pharmacopeia (USP) Reference Standard, Aniline, Mesalazine EP Impurity K, Sodium Cyclamate EP Impurity B, Trimethoprim EP Impurity K, Anilin, Aniline, Anilina, ai3-03053, Aminophen, Benzamine, C.I. 76000, Phenylamine, BENZENAMINE, amino-benzen, Aminobenzene, BENZENEAMINE, anilin(czech), C.I. Oxidation Base

Benzenamine is a primary arylamine in which an amino functional group is substituted for one of the benzene hydrogens.
It is a primary arylamine and a member of Benzenamines.
Benzenamine, phenylamine or aminobenzene is an organic compound with the formula C6H5NH2.

Consisting of an amine attached to a benzene ring, Benzenamine is the prototypical aromatic amine.
Being a precursor to many industrial chemicals, Benzenamine's main use is in the manufacture of precursors to polyurethane.
Like most volatile amines, Benzenamine possesses the somewhat unpleasant odour of rotten fish.

Benzenamine is colorless, but it slowly oxidizes and resinifies in air, giving a red-brown tint to aged samples.
Benzenamine is an organic chemical compound, specifically a primary aromatic amine.
Benzenamine consists of a benzene ring attached to an amino group.

Benzenamine is oily and, although colorless, it can be slowly oxidized and resinified in air to form impurities which can give it a red-brown tint.
Benzenamine's boiling point is 184 degree centigrade and its melting point is -6 degree centigrade.

Benzenamine is a liquid at room temperature.
Like most volatile amines, Benzenamine possesses a somewhat unpleasant odour of rotten fish, and also has a burning aromatic taste.
Benzenamine reacts with strong acids to form salts containing the anilinium (or phenylammonium) ion (C6H5-NH3+), and reacts with acyl halides (such as acetyl chloride (ethanoyl chloride), CH3COCl) to form amides.

The amides formed from Benzenamine are sometimes called anilides, for example CH3-CO-NH-C6H5 is acetanilide, for which the modern name is N-phenyl ethanamide.
Like phenols, Benzenamine derivatives are highly reactive in electrophilic substitution reactions.

For example, sulfonation of Benzenamine produces sulfanilic acid, which can be converted to sulfanilamide.
Sulfanilamide is one of the sulfa drugs which were widely used as antibacterial in the early 20th century.
Benzenamine was first isolated from the destructive distillation of indigo in 1826 by Otto Unverdorben.

In 1834, Friedrich Runge isolated from coal tar a substance which produced a beautiful blue color on treatment with chloride of lime; this he named kyanol or cyanol.
In 1841, C. J. Fritzsche showed that by treating indigo with caustic potash it yielded an oil, which he named Benzenamine, from the specific name of one of the indigo-yielding plants, Indigofera anil, anil being derived from the Sanskrit, dark-blue.

Benzenamine, chemically known as phenylamine, is an organic compound with the molecular formula C6H5NH2 and a molecular weight of 93.13 g/mol.
Benzenamine is a primary aromatic amine characterized by a benzene ring attached to an amino group (-NH2), appearing as a colorless to light yellow oily liquid with a characteristic aromatic amine-like odor that darkens to brown upon exposure to air and light.

Slightly soluble in water (approximately 3.5 g/100 mL at 25 °C) and miscible with most organic solvents, Benzenamine has a melting point of -6 °C, a boiling point of 184 °C, and a density of 1.02 g/cm³ at 20 °C.
Benzenamine (From Portuguese: anil, meaning 'indigo shrub', and -ine indicating a derived substance) is an organic compound with the formula C6H5NH2.

Consisting of a phenyl group (−C6H5) attached to an amino group (−NH2), Benzenamine is the simplest aromatic amine.
Benzenamine is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis.
Benzenamine's main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals.

Like most volatile amines, Benzenamine has the odor of rotten fish.
Benzenamine ignites readily, burning with a smoky flame characteristic of aromatic compounds.
Relative to benzene, Benzenamine is "electron-rich".

Benzenamine thus participates more rapidly in electrophilic aromatic substitution reactions.
Likewise, it is also prone to oxidation: while freshly purified Benzenamine is an almost colorless oil, exposure to air results in gradual darkening to yellow or red, due to the formation of strongly colored, oxidized impurities.

Benzenamine can be diazotized to give a diazonium salt, which can then undergo various nucleophilic substitution reactions.
Like other amines, Benzenamine is both a base (pKaH = 4.6) and a nucleophile, although less so than structurally similar aliphatic amines.
Because an early source of the benzene from which they are derived was coal tar, Benzenamine dyes are also called coal tar dyes.

USES and APPLICATIONS of BENZENAMINE:
Benzenamine is used a standard sample for measuring the refractive index.
Benzenamine is used halogen, chromate, vanadate, nitrite and carboxylic acid were detected.
Benzenamine is used for the pharmaceutical industry, organic synthesis.

Benzenamine is primarily utilized as a chemical intermediate in the manufacture of dyes, pharmaceuticals, polyurethane polymers, rubber additives, and agricultural products, it also serves as a solvent in certain applications.
Benzenamine is predominantly used for the preparation of methylenediBenzenamine and related compounds by condensation with formaldehyde.

The diamines are condensed with phosgene to give methylene diphenyl diisocyanate, a precursor to urethane polymers.
Other uses of Benzenamine include rubber processing chemicals (9%), herbicides (2%), and dyes and pigments (2%).
As additives to rubber, Benzenamine derivatives such as phenylenediamines and diphenylamine, are antioxidants.

Illustrative of the drugs prepared from Benzenamine is paracetamol (acetaminophen, Tylenol).
The principal use of Benzenamine in the dye industry is as a precursor to indigo, the blue of blue jeans.
Benzenamine oil is also used for mushroom identification.

Kerrigan's 2016 Agaricus of North America P45: "In fact I recommend switching to the following modified test.
Frank (1988) developed an alternative formulation in which Benzenamine oil is combined with glacial acetic acid (GAA, essentially distilled vinegar) in a 50:50 solution.

GAA is a much safer, less reactive acid.
This single combined reagent is relatively stable over time.
A single spot or line applied to the pileus (or other surface).

In my experience the newer formulation works as well as Schaffer's while being safer and more convenient."
Benzenamine is not typically used as a consumer product itself; it is primarily an intermediate that feeds into other chemical manufacturing processes.

Benzenamine is used to manufacture other chemicals, especially dyes, photographic chemicals, agricultural chemicals and others.
Benzenamine is used in rubber accelerators and anti-oxidants, dyes and intermediates, photographic chemicals, as isocyanates for urethane foams, in pharmaceuticals, explosives, petroleum refining; and in production of diphenylamine, phenolics, herbicides and fungicides.

Benzenamine is also used in the manufacture of polyurethanes, rubber processing chemicals, pesticides, fibres, dyes and pigments, photographic chemicals, and pharmaceuticals.

-Uses & Applications of Benzenamine:
Benzenamine is an important industrial chemical intermediate widely used in the synthesis of:
*Dyes and pigments (azo dyes, indigo dye)
*Rubber processing chemicals (antioxidants, accelerators)
*Pharmaceutical intermediates
*Herbicides and pesticides
*Polyurethane precursors (e.g., Benzenamine used to make methylene diphenyl diisocyanate MDI)
*Photographic and rubber chemicals
*Chemical intermediates for fine chemicals

PROPERTIES, BENEFITS & CHARACTERISTICS of BENZENAMINE:
*Reactivity: 
As a primary aromatic amine, Benzenamine participates in electrophilic aromatic substitution reactions, diazotization, and acylation.

*Solvency: 
Benzenamine is moderately soluble in organic solvents; useful as a solvent for certain organic synthesis steps.

*Feedstock: 
Key intermediate for the production of many industrial chemicals rather than an end-use product.

*Activation of Ring: 
The -NH₂ group strongly activates the aromatic ring toward substitution reactions, making Benzenamine valuable in synthetic chemistry.

CHEMICAL PROPERTIES of BENZENAMINE:
Benzenamine is a primary aromatic amine consisting of an amine group (-NH₂) attached directly to a benzene ring.
This structure gives Benzenamine weak basicity, and it undergoes typical aromatic amine reactions such as diazotization and acylation.
The amine group activates the benzene ring for electrophilic substitution, especially at the ortho and para positions relative to the -NH₂ group.
Benzenamine is also slightly reactive toward oxidizing agents and darkens upon oxidation or prolonged exposure to air and light.

OTHER REACTIONS of BENZENAMINE:
Benzenamine reacts with nitrobenzene to produce phenazine in the Wohl–Aue reaction.
Hydrogenation gives cyclohexylamine.
Being a standard reagent in laboratories, Benzenamine is used for many niche reactions.

Its acetate is used in the Benzenamine acetate test for carbohydrates, identifying pentoses by conversion to furfural.
Benzenamine is used to stain neural RNA blue in the Nissl stain.
In addition, Benzenamine is the starting component in the production of diglycidyl Benzenamine.
Epichlorohydrin is the other main ingredient.

HISTORY of BENZENAMINE:
Benzenamine was first isolated in 1826 by Otto Unverdorben by destructive distillation of indigo.
He called it Crystallin.
In 1834, Friedlieb Runge isolated a substance from coal tar that turned a beautiful blue color when treated with chloride of lime.

He named it kyanol or cyanol.
In 1840, Carl Julius Fritzsche (1808–1871) treated indigo with caustic potash and obtained an oil that he named Benzenamine, after an indigo-yielding plant, anil (Indigofera suffruticosa).

In 1842, Nikolay Nikolaevich Zinin reduced nitrobenzene and obtained a base that he named benzidam.
In 1843, August Wilhelm von Hofmann showed that these were all the same substance, known thereafter as phenylamine or Benzenamine.

SYNTHETIC DYE INDUSTRY of BENZENAMINE:
In 1856, while trying to synthesise quinine, von Hofmann's student William Henry Perkin discovered mauveine.
Mauveine quickly became a commercial dye.
Other synthetic dyes followed, such as fuchsin, safranin, and induline.
At the time of mauveine's discovery, Benzenamine was expensive.
Soon thereafter, applying a method reported in 1854 by Antoine Béchamp, it was prepared "by the ton".
The Béchamp reduction enabled the evolution of a massive dye industry in Germany.
Today, the name of BASF, originally Badische Anilin- und Soda-Fabrik (English: Baden Benzenamine and Soda Factory), now the largest chemical supplier, echoes the legacy of the synthetic dye industry, built via Benzenamine dyes and extended via the related azo dyes.
The first azo dye was Benzenamine yellow.

STRUCTURE of BENZENAMINE:
Aryl-N distances
In Benzenamine, the C−N bond length is 1.41 Å, compared to the C−N bond length of 1.47 Å for cyclohexylamine, indicating partial π-bonding between C(aryl) and N.
The length of the chemical bond of C(aryl)−NH2 in Benzenamines is highly sensitive to substituent effects.
The C−N bond length is 1.34 Å in 2,4,6-trinitroBenzenamine vs 1.44 Å in 3-methylBenzenamine.

Pyramidalization
The amine group in Benzenamines is a slightly pyramidalized molecule, with hybridization of the nitrogen somewhere between sp3 and sp2.
The nitrogen is described as having high p character.

The amino group in Benzenamine is flatter (i.e., it is a "shallower pyramid") than that in an aliphatic amine, owing to conjugation of the lone pair with the aryl substituent.
The observed geometry reflects a compromise between two competing factors: 

1) stabilization of the N lone pair in an orbital with significant s character favors pyramidalization (orbitals with s character are lower in energy), while 

2) delocalization of the N lone pair into the aryl ring favors planarity (a lone pair in a pure p orbital gives the best overlap with the orbitals of the benzene ring π system).
Consistent with these factors, substituted Benzenamines with electron donating groups are more pyramidalized, while those with electron withdrawing groups are more planar.

In the parent Benzenamine, the lone pair is approximately 12% s character, corresponding to sp7.3 hybridization.
For comparison, alkylamines generally have lone pairs in orbitals that are close to sp3.

The pyramidalization angle between the C–N bond and the bisector of the H–N–H angle is 142.5°.
For comparison, in more strongly pyramidal amine group in methylamine, this value is ~125°, while that of the amine group in formamide has an angle of 180°.

PRODUCTION of BENZENAMINE:
Industrial Benzenamine production involves hydrogenation of nitrobenzene (typically at 200–300 °C) in the presence of metal catalysts.
Approximately 4 billion kilograms are produced annually.
Catalysts include nickel, copper, palladium, and platinum, and newer catalysts continue to be discovered.
The reduction of nitrobenzene to Benzenamine was first performed by Nikolay Zinin in 1842, using sulfide salts (Zinin reaction).

The reduction of nitrobenzene to Benzenamine was also performed as part of reductions by Antoine Béchamp in 1854, using iron as the reductant (Bechamp reduction).
These stoichiometric routes remain useful for specialty Benzenamines.
Benzenamine can alternatively be prepared from ammonia and phenol derived from the cumene process.

In commerce, three brands of Benzenamine are distinguished: Benzenamine oil for blue, which is pure Benzenamine; Benzenamine oil for red, a mixture of equimolecular quantities of Benzenamine and ortho- and para-toluidines; and Benzenamine oil for safranine, which contains Benzenamine and ortho-toluidine and is obtained from the distillate (échappés) of the fuchsine fusion.

RELATED BENZENAMINE DERIVATIVES:
Many analogues and derivatives of Benzenamine are known where the phenyl group is further substituted.
These include toluidines, xylidines, chloroBenzenamines, aminobenzoic acids, nitroBenzenamines, and many others.
They also are usually prepared by nitration of the substituted aromatic compounds followed by reduction.
For example, this approach is used to convert toluene into toluidines and chlorobenzene into 4-chloroBenzenamine.
Alternatively, using Buchwald-Hartwig coupling or Ullmann reaction approaches, aryl halides can be aminated with aqueous or gaseous ammonia.

RELATED COMPOUNDS of BENZENAMINE:
-Related aromatic 
amines    1-Naphthylamine
2-Naphthylamine

-Related compounds    
Phenylhydrazine
Nitrosobenzene
Nitrobenzene

REACTIONS of BENZENAMINE:
The chemistry of Benzenamine is rich because the compound has been cheaply available for many years.
Below are some classes of its reactions.

Oxidation
The oxidation of Benzenamine has been heavily investigated, and can result in reactions localized at nitrogen or more commonly results in the formation of new C-N bonds.
In alkaline solution, azobenzene results, whereas arsenic acid produces the violet-coloring matter violBenzenamine.

Chromic acid converts it into quinone, whereas chlorates, in the presence of certain metallic salts (especially of vanadium), give Benzenamine black.
Hydrochloric acid and potassium chlorate give chloranil.

Potassium permanganate in neutral solution oxidizes it to nitrobenzene; in alkaline solution to azobenzene, ammonia, and oxalic acid; in acid solution to Benzenamine black.

Hypochlorous acid gives 4-aminophenol and para-amino diphenylamine.
Oxidation with persulfate affords a variety of polyBenzenamines.
These polymers exhibit rich redox and acid-base properties.

Electrophilic reactions at ortho- and para- positions
Like phenols, Benzenamine derivatives are highly susceptible to electrophilic substitution reactions.
Its high reactivity reflects that Benzenamine is an enamine, which enhances the electron-donating ability of the ring.

For example, reaction of Benzenamine with sulfuric acid at 180 °C produces sulfanilic acid, H2NC6H4SO3H.
If bromine water is added to Benzenamine, the bromine water is decolourised and a white precipitate of 2,4,6-tribromoBenzenamine is formed.
To generate the mono-substituted product, a protection with acetyl chloride is required.

The reaction to form 4-bromoBenzenamine is to protect the amine with acetyl chloride, then hydrolyse back to reform Benzenamine.
The largest scale industrial reaction of Benzenamine involves its alkylation with formaldehyde.

An idealized equation is shown:
2 C6H5NH2 + CH2O → CH2(C6H4NH2)2 + H2O
The resulting diamine is the precursor to 4,4'-MDI and related diisocyanates.

Reactions at nitrogen
Basicity
Benzenamine is a weak base.
Aromatic amines such as Benzenamine are, in general, much weaker bases than aliphatic amines.
Benzenamine reacts with strong acids to form the anilinium (or phenylammonium) ion (C6H5−NH3+).

Traditionally, the weak basicity of Benzenamine is attributed to a combination of inductive effect from the more electronegative sp2 carbon and resonance effects, as the lone pair on the nitrogen is partially delocalized into the pi system of the benzene ring.
Missing in such an analysis is consideration of solvation.
Benzenamine is, for example, more basic than ammonia in the gas phase, but ten thousand times less so in aqueous solution.

Acylation
Benzenamine reacts with acyl chlorides such as acetyl chloride to give amides.
The amides formed from Benzenamine are sometimes called anilides, for example CH3−C(=O)−NH−C6H5 is acetanilide.
At high temperatures Benzenamine and carboxylic acids react to give the anilides.

N-Alkylation
N-Methylation of Benzenamine with methanol at elevated temperatures over acid catalysts gives N-methylBenzenamine and N,N-dimethylBenzenamine.
C6H5NH2 + 2 CH3OH → C6H5N(CH3)2 + 2H2O
N-MethylBenzenamine and N,N-dimethylBenzenamine are colorless liquids with boiling points of 193–195 °C and 192 °C, respectively.
These derivatives are of importance in the color industry.

Carbon disulfide derivatives
Boiled with carbon disulfide, it gives sulfocarbanilide (diphenylthiourea) (S=C(−NH−C6H5)2), which may be decomposed into phenyl isothiocyanate (C6H5−N=C=S), and triphenyl guanidine (C6H5−N=C(−NH−C6H5)2).

Diazotization
Benzenamine and its ring-substituted derivatives react with nitrous acid to form diazonium salts.
One example is benzenediazonium tetrafluoroborate.

Through these intermediates, the amine group can be converted to a hydroxyl (−OH), cyanide (−CN), or halide group (−X, where X is a halogen) via Sandmeyer reactions.
This diazonium salt can also be reacted with NaNO2 and phenol to produce a dye known as benzeneazophenol, in a process called coupling.
The reaction of converting primary aromatic amine into diazonium salt is called diazotisation.

In this reaction primary aromatic amine is allowed to react with sodium nitrite and 2 moles of HCl, which is known as "ice cold mixture" because the temperature for the reaction was as low as 0.5 °C.
The benzene diazonium salt is formed as major product alongside the byproducts water and sodium chloride.

NATURE of BENZENAMINE:
Benzenamine is a colorless or light yellow transparent liquid.
Pure Benzenamine is a colorless transparent liquid with special odor.
1 g of Benzenamine can be dissolved in 28.6 mL water, 15.7 mL boiling water, with ethanol, ether, benzene and other organic solvents miscible, with water vapor evaporation.

The solubility of Benzenamine in water increases with the increase of temperature.
When the temperature is higher than 167.5 ℃, Benzenamine and water can be dissolved in any proportion.
The solubility of Benzenamine in Benzenamine salt is very large, and 50% of Benzenamine hydrochloride can be miscible with Benzenamine in any proportion.
In the air oxygen, light irradiation or high temperature, Benzenamine is easily oxidized.

PREPARATION METHOD of BENZENAMINE:
Benzenamine is prepared by reduction of nitrobenzene with hydrogen in the presence of a catalyst.

DEVELOPMENTS IN MEDICINE of BENZENAMINE:
In the late 19th century, derivatives of Benzenamine such as acetanilide and phenacetin emerged as analgesic drugs, with their cardiac-suppressive side effects often countered with caffeine.
Also in the late 19th century, Ehrlich found that the Benzenamine dye methylene blue works as an antimalarial drug.

He hypothesized that dyes that selectively stain pathogens over tissue would prefentially harm pathogens, leading to his "magic bullet" concept.
During the first decade of the 20th century, while trying to modify synthetic dyes to treat African sleeping sickness, Paul Ehrlich – who had coined the term chemotherapy for his 'magic bullet' approach to medicine – failed and switched to modifying Béchamp's atoxyl, the first organic arsenical drug, and serendipitously obtained a treatment for syphilis – salvarsan – the first successful chemotherapy agent.

Salvarsan's targeted microorganism, not yet recognized as a bacterium, was still thought to be a parasite, and medical bacteriologists, believing that bacteria were not susceptible to the chemotherapeutic approach, overlooked Alexander Fleming's report in 1928 on the effects of penicillin.

In 1932, Bayer sought medical applications of its dyes.
Gerhard Domagk identified as an antibacterial a red azo dye, introduced in 1935 as the first antibacterial drug, prontosil, soon found at Pasteur Institute to be a prodrug degraded in vivo into sulfanilamide – a colorless intermediate for many, highly colorfast azo dyes – already with an expired patent, synthesized in 1908 in Vienna by the researcher Paul Gelmo for his doctoral research.

By the 1940s, over 500 related sulfa drugs were produced.
Medications in high demand during World War II (1939–45), these first miracle drugs, chemotherapy of wide effectiveness, propelled the American pharmaceutics industry.

In 1939, at Oxford University, seeking an alternative to sulfa drugs, Howard Florey developed Fleming's penicillin into the first systemic antibiotic drug, penicillin G.
Gramicidin, developed by René Dubos at Rockefeller Institute in 1939, was the first antibiotic, yet its toxicity restricted it to topical use.
After World War II, Cornelius P. Rhoads introduced the chemotherapeutic approach to cancer treatment.

*Rocket fuel
Some early American rockets, such as the Aerobee and WAC Corporal, used a mixture of Benzenamine and furfuryl alcohol as a fuel, with nitric acid as an oxidizer.
The combination is hypergolic, igniting on contact between fuel and oxidizer.
Benzenamine is also dense, and can be stored for extended periods.
Benzenamine was later replaced by hydrazine.

CHEMICAL STRUCTURE AND BASIC PROPERTIES of BENZENAMINE:
Molecular Structure
Benzenamine has the molecular formula C₆H₅NH₂, consisting of a benzene ring (C₆H₅) covalently bonded to an amino group (NH₂).
In Benzenamine's Lewis structure, the benzene ring is represented with alternating single and double bonds, while the nitrogen atom of the NH₂ group is bonded to the ipso carbon and bears two hydrogen atoms and a lone pair of electrons.

The molecule exhibits resonance delocalization, where the lone pair on the nitrogen atom conjugates with the π-system of the aromatic ring.
This results in several contributing resonance structures: two primary forms show the nitrogen with sp³ hybridization and a localized lone pair (predicting an H-N-H angle near 107°), while three additional forms depict sp² hybridization at nitrogen, with the lone pair participating in π-bonding to the ring and positive charge on nitrogen (predicting an H-N-H angle near 120°).

The actual structure is a hybrid, with partial double-bond character in the C-N linkage, shortening the bond length and influencing electrophilic substitution preferences at ortho and para positions.
Experimental bond lengths include a C-N distance of 1.402 Å (microwave spectroscopy) or 1.406 Å (electron diffraction), compared to typical single C-N bonds around 1.47 Å in aliphatic amines, reflecting resonance effects.

Aromatic C-C bonds average 1.39–1.40 Å, and N-H bonds are approximately 1.00 Å.
Bond angles feature an H-N-H angle of 113.1° (microwave data), intermediate between sp³ and sp² predictions, and ring angles near 120° for planarity.

The NH₂ group is nonplanar, twisted out of the ring plane by an angle of approximately 42°, with the nitrogen atom displaced about 0.05 Å above the ring.
Benzenamine lacks chiral centers and possesses a plane of symmetry through the ring and nitrogen, rendering it achiral with no stereoisomers.
The aromatic system remains planar, while amine inversion occurs rapidly due to a low barrier of about 1.5 kcal/mol.

PHYSICAL PROPERTIES of BENZENAMINE:
Benzenamine is a colorless to slightly yellow oily liquid when freshly distilled, which darkens to brownish upon exposure to air and light, exhibiting a characteristic aromatic amine odor often described as musty or fishy.
The density of Benzenamine is 1.022 g/cm³ at 25 °C.

Benzenamine's refractive index is 1.586 at 20 °C.
Benzenamine is slightly soluble in water, with a solubility of 3.4 g/100 mL at 20 °C, but it is miscible with ethanol and diethyl ether.
This solubility behavior arises from the polarity imparted by the amino group attached to the benzene ring.

The dynamic viscosity of Benzenamine is 3.71 mPa•s at 25 °C, while its surface tension is 42.1 mN/m at the same temperature.
Benzenamine is a colourless to brown, oily liquid which darkens on exposure to air and light.

Benzenamine has a characteristic amine odour (detectable at 0.6 to 10 ppm ) and burning taste.
Benzenamine is hygroscopic.
Benzenamine is moderately soluble in water.

Benzenamine is miscible with alcohol, benzene, chloroform, carbon tetrachloride, acetone, and most organic solvents.
Melting Point: -6.2°C
Boiling Point: 184°C
Specific Gravity: 1.0217
Vapour Density: 3.22
1 ppm = 3.8 mg/m3
Formula weight 93.128

CHEMICAL PROPERTIES of BENZENAMINE:
Benzenamine darkens on exposure to air and light.
Benzenamine decomposes on heating at temperatures above 190°C, or on burning producing toxic and corrosive fumes (ammonia, nitrogen oxides, and carbon monoxide) and flammable vapours.

Benzenamine is a weak base.
Reacts vigorously with strong oxidants, acids, acetic anhydride, chloromelamine monomers, beta-propiolactone, and epichlorohydrin causing fire and explosion hazard.

Benzenamine reacts with metals such as sodium, potassium, and calcium, producing flammable hydrogen gas.
Benzenamine attacks copper and its alloys.

Benzenamine is a clear to slightly yellow liquid with a characteristic odor.
Benzenamine does not readily evaporate at room temperature.
Benzenamine is slightly soluble in water and mixes readily with most organic solvents.

Benzenamine is used to make a wide variety of products such as polyurethane foam, agricultural chemicals, synthetic dyes, antioxidants, stabilizers for the rubber industry, herbicides, varnishes and explosives.
Benzenamine appears as a yellowish to brownish oily liquid with a musty fishy odor.

Melting point of Benzenamine is -6 °C; boiling point 184 °C; flash point 158 °F.
Benzenamine is denser than water (8.5 lb / gal) and slightly soluble in water.
Vapors of Benzenamine is heavier than air.

THERMODYNAMIC AND PHASE PROPERTIES of BENZENAMINE:
*Thermodynamic Properties
Benzenamine, a liquid at standard conditions, exhibits key thermodynamic properties that reflect its molecular structure and intermolecular forces.

The standard enthalpy of formation for liquid Benzenamine at 298.15 K and 1 bar is reported as 31.3 ± 0.84 kJ/mol, determined through combustion calorimetry.
This positive value indicates an endothermic formation process relative to the elements in their standard states.

Similarly, the standard molar entropy of liquid Benzenamine at the same conditions is 191.30 J/mol•K, derived from low-temperature heat capacity measurements and third-law entropy calculations.
The heat capacity of liquid Benzenamine at constant pressure (C_p) is temperature-dependent, with a value of 192.05 J/mol•K at 298.15 K over the range 15–300 K.

This can be modeled by the linear equation in calories per mole per kelvin: C_p(liq) = 33.71 + 0.0409 T, where T is in kelvin, corresponding to approximately 141 + 0.171 T J/mol•K after unit conversion.
Such data are essential for understanding energy storage and transfer in Benzenamine-based systems.
Phase transition enthalpies provide insight into the energy barriers for melting and boiling.

The enthalpy of fusion is 10.54 kJ/mol at the melting point of 267.1 K, measured calorimetrically.
The boiling point is 457.3 K, with an enthalpy of vaporization near 298 K approximated at 53 kJ/mol based on low-temperature measurements and correlations.

More precisely, the vaporization enthalpy over 298–333 K follows the correlation Δ_vap H = 80.66 exp(-0.3744 T_r) (1 - T_r)^{0.3744} kJ/mol, where T_r = T / 699 K is the reduced temperature.
These properties, compiled from experimental calorimetry and referenced in authoritative thermochemical databases, underscore Benzenamine's stability and utility in chemical processes.

The vapor pressure of Benzenamine, an important thermodynamic property influencing its volatility and phase behavior, is typically modeled using empirical correlations derived from experimental measurements over a range of temperatures.
These data are essential for understanding equilibrium conditions in processes involving evaporation or distillation.

The Antoine equation provides a widely used correlation for vapor pressure as a function of temperature:
log10P=A−B/(T+C)
where P is the vapor pressure in bar and T is the temperature in kelvin.

For Benzenamine, reliable parameters valid over the temperature range 304 to 457 K are A=4.34541, B=1661.858, and C=−74.048.
These coefficients were calculated by NIST from experimental vapor pressure measurements conducted by Hatton et al. in 1962, ensuring accuracy for practical applications up to the normal boiling point of approximately 457 K.

Representative tabulated vapor pressure values, based on standard compilations and consistent with Antoine correlations, are presented below for key temperatures.
These illustrate the low volatility of Benzenamine at ambient conditions, increasing significantly near its boiling point.

Values were derived using the Antoine parameters and cross-verified with handbook data; the critical pressure at 698.8 K marks the upper limit where distinct vapor-liquid phases cease to exist.
Benzenamine is frequently purified by vacuum distillation to minimize thermal decomposition, as its normal boiling point of 184 °C can lead to side reactions at atmospheric pressure.

Under reduced pressure, the boiling point decreases significantly; for instance, at 10 mmHg (1.33 kPa), Benzenamine boils at approximately 68 °C, calculated using Antoine equation parameters derived from experimental vapor pressure data.
Benzenamine does not form a true minimum-boiling azeotrope with water, owing to its partial miscibility, which enables efficient purification via steam distillation.

In this process, the heterogeneous vapor-liquid equilibrium results in a mixture boiling at around 98.5–99 °C at atmospheric pressure, with the distillate containing approximately 19–20 wt% Benzenamine and the remainder water; this lower effective temperature facilitates impurity removal without excessive heating.

For commercial-grade Benzenamine, purity is assessed through ASTM or equivalent distillation tests, where high-purity samples (≥99 wt%) exhibit a narrow distillation range: typically, at least 95% of a 100 mL sample distills within 1 °C, centered around 184 °C at 760 mmHg, ensuring minimal low- or high-boiling contaminants.

Impurities significantly influence distillation behavior.
Water, as a lower-boiling component, promotes boiling point depression in steam distillation setups but can elevate the boiling point slightly in anhydrous mixtures due to colligative effects.

Nitrobenzene, a common residual from synthesis (boiling point 211 °C), causes boiling point elevation proportional to its concentration, necessitating multiple stages for separation.
Colorless oily flammable liquid with strong odor.

Melting Point -6.3 ℃, boiling point 184 ℃, 68.3 ℃(1.33kPa), relative density 1.0217(20/4 ℃), refractive index 1.5863, Flash Point (Open Cup) 70 ℃, spontaneous ignition point 770.
In the open air or light will gradually turn brown.

Benzenamine can be volatilized with water vapor.
Benzenamine can be miscible with ethanol, ether, chloroform and many other organic solvents.
The solubility (weight percentage) of Benzenamine in water is 3.7% at 30 °C, 4.2% at 50 °C, and 110 at 8.0% °C.

There are alkaline, can be generated with hydrochloric acid hydrochloride, and sulfuric acid sulfate.
Benzenamine is an important intermediate.
The more important products produced by Benzenamine were 300.

There are about 80 Benzenamine manufacturers in the world, with an annual total production capacity of more than 2.7 million t/a and an output of about 2.3 million t.
The main consumption field is MDI, in 2000, its consumption accounted for about 84% of the total consumption of Benzenamine.
Benzenamine is mainly consumed in MDI, dye industry, rubber additives, pharmaceuticals, pesticides and organic intermediates.

PHYSICAL and CHEMICAL PROPERTIES of BENZENAMINE:
Common Name: Benzenamine
Also Known As: Aniline
IUPAC Name: Benzenamine
Molecular Formula: C₆H₇N
Molecular Weight: ≈ 93.13 g/mol
CAS Number: 62-53-3
EC / EINECS Number: 200-539-3
Appearance: Colorless to slightly yellow, oily liquid; often darkens on air/light exposure
Odor: Characteristic sweet amine-like odor, detectable at low ppm
Density: ~1.02–1.03 g/cm³ at 20–25 °C

Melting Point: ~-6.3 °C
Boiling Point: ~184 °C
Vapor Pressure: ~0.49–0.7 mmHg at 20–25 °C
Vapor Density: ~3.2 (air = 1)
Solubility in Water: ~3.5–3.6 g/100 mL at 20 °C
Solubility: Miscible with alcohols, ethers, chloroform, benzene, acetone
Flash Point: ~70 °C (closed cup)
Autoignition Temperature: ~540–615 °C
Uses: Industrial intermediate (dyes, polyurethane, rubber chemicals)

Chemical Formula: C6H5NH2
Molar Mass: 93.129 g·mol−1
Appearance: Colorless liquid
Density: 1.0297 g/mL
Melting Point: −6.30 °C
Boiling Point: 184.13 °C
Solubility in Water: 3.6 g/(100 mL) at 20 °C
Vapor Pressure: 0.6 mmHg at 20 °C
Acidity (pKa): 4.63 (conjugate acid; H2O)

Magnetic Susceptibility (χ): −62.95·10−6 cm3/mol
Refractive Index (nD): 1.58364
Viscosity: 3.71 cP at 25 °C
Std Enthalpy of Combustion (ΔcH⦵298): −3394 kJ/mol
Flash Point: 70 °C
Autoignition Temperature: 770 °C
Explosive Limits: 1.3–11%
XLogP3: 0.9

Hydrogen Bond Donor Count: 1
Hydrogen Bond Acceptor Count: 1
Rotatable Bond Count: 0
Exact Mass: 93.057849228 Da
Monoisotopic Mass: 93.057849228 Da
Topological Polar Surface Area: 26 Ų
Heavy Atom Count: 7
Formal Charge: 0
Complexity: 46.1

Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes
CAS: 62-53-3
EINECS: 200-539-3
InChI: InChI=1/C6H7N/c7-6-4-2-1-3-5-6/h1-5H,7H2

Molecular Formula: C6H7N
Molar Mass: 93.13
Density: 1.022 g/mL at 25 °C
Melting Point: -6 °C
Boiling Point: 184 °C
Flash Point: 76 °C
Water Solubility: 36 g/L (20 ºC)
Solubility: Water: soluble
Vapor Pressure: 0.7 mm Hg at 25 °C
Vapor Density: 3.22 (vs air)
Appearance: Liquid
Specific Gravity: 1.021

Color: APHA: ≤250
Odor: Sweet, amine-like odor detectable at 0.6 to 10 ppm
Exposure Limit: TLV-TWA skin 2 ppm (8 mg/m3) (ACGIH), 5 ppm (19 mg/m3) (MSHA, OSHA, and NIOSH); IDLH 100 ppm (NIOSH)
Merck: 14,659
BRN: 605631
pKa: 4.63
pH: 8.8 (36 g/L, H2O, 20 °C)
Storage Condition: 2-8 °C
Stability: Stable. Incompatible with oxidizing agents, bases, acids, iron and iron salts, zinc, aluminium. Light sensitive. Combustible
Explosive Limit: 1.2-11%
Refractive Index: n20/D 1.586

FIRST AID MEASURES of BENZENAMINE:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of BENZENAMINE:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of BENZENAMINE:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of BENZENAMINE:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of BENZENAMINE:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of BENZENAMINE:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available