PRODUCTS

ISOQUINOLINE

CAS NUMBER: 119-65-3

EC NUMBER: 204-341-8

MOLECULAR FORMULA: C9H7N

MOLECULAR WEIGHT: 129.16

IUPAC NAME: isoquinoline

Isoquinoline is a heterocyclic aromatic organic compound.
Isoquinoline is a structural isomer of quinoline.
Isoquinoline and quinoline are benzopyridines, which are composed of a benzene ring fused to a pyridine ring.
In a broader sense, the term Isoquinoline is used to make reference to isoquinoline derivatives.
1-Benzylisoquinoline is the structural backbone in naturally occurring alkaloids including papaverine.
The Isoquinoline ring in these natural compound derives from the aromatic amino acid tyrosine.

Properties:
Isoquinoline is a colorless hygroscopic liquid at temperatures above its melting point with a penetrating, unpleasant odor.
Impure samples can appear brownish, as is typical for nitrogen heterocycles.
Isoquinoline crystallizes in platelets that have a low solubility in water but dissolve well in:
-ethanol
-acetone
-diethyl ether
-carbon disulfide
-other common organic solvents

Isoquinoline is also soluble in dilute acids as the protonated derivative.
Being an analog of pyridine, isoquinoline is a weak base, with a pKa of 5.14.
Isoquinoline protonates to form salts upon treatment with strong acids, such as HCl.
Isoquinoline forms adducts with Lewis acids, such as BF3.

Production:
Isoquinoline was first isolated from coal tar in 1885 by Hoogewerf and van Dorp.
They isolated Isoquinoline by fractional crystallization of the acid sulfate.
Weissgerber developed a more rapid route in 1914 by selective extraction of coal tar, exploiting the fact that isoquinoline is more basic than quinoline.
Isoquinoline can then be isolated from the mixture by fractional crystallization of the acid sulfate.

Although isoquinoline derivatives can be synthesized by several methods, relatively few direct methods deliver the unsubstituted isoquinoline.
The Pomeranz–Fritsch reaction provides an efficient method for the preparation of isoquinoline.
This reaction uses a benzaldehyde and aminoacetoaldehyde diethyl acetal, which in an acid medium react to form isoquinoline.
Alternatively, benzylamine and a glyoxal acetal can be used, to produce the same result using the Schlittler-Müller modification

In the Bischler–Napieralski reaction an β-phenylethylamine is acylated and cyclodehydrated by a Lewis acid, such as phosphoryl chloride or phosphorus pentoxide.
The resulting 1-substituted 3,4-dihydroisoquinoline can then be dehydrogenated using palladium.
The following Bischler–Napieralski reaction produces papaverine

The Pictet–Gams reaction and the Pictet–Spengler reaction are both variations on the Bischler–Napieralski reaction.
Isoquinoline is a Pictet–Gams reaction works similarly to the Bischler–Napieralski reaction; the only difference being that an additional hydroxy group in the reactant provides a site for dehydration under the same reaction conditions as the cyclization to give the isoquinoline rather than requiring a separate reaction to convert a dihydroisoquinoline intermediate.

Applications of derivatives:
Isoquinolines find many applications, including:
-anesthetics; dimethisoquin is one example (shown below)
-antihypertension agents, such as quinapril and debrisoquine (all derived from 1,2,3,4-tetrahydroisoquinoline).
-antiretroviral agents, such as saquinavir with an isoquinolyl functional group, (shown below)
-vasodilators, a well-known example, papaverine, shown below

Bisbenzylisoquinolinium compounds are compounds similar in structure to tubocurarine.
They have two isoquinolinium structures, linked by a carbon chain, containing two ester linkages.
Isoquinoline is used in the manufacture of dyes, paints, insecticides and antifungals.
Isoquinoline is also used as a solvent for the extraction of resins and terpenes, and as a corrosion inhibitor.

Isoquinoline is an ortho-fused heteroarene that is a benzopyridine in which the N atom not directly attached to the benzene ring.
Isoquinoline is a mancude organic heterobicyclic parent, an azaarene, an ortho-fused heteroarene and a member of isoquinolines.

Isoquinoline is a low-melting nitrogenous base C9H7N that is associated with its isomer quinoline in coal tar and that is the parent structure in many alkaloids (as narcotine and papaverine)
Isoquinoline is a group of compounds with the heterocyclic ring structure of benzo(c)pyridine.
Isoquinoline is an ortho-fused heteroarene that is a benzopyridine in which the N atom not directly attached to the benzene ring.
Isoquinoline is a heterocyclic aromatic organic compound.

Isoquinoline is a structural isomer of quinoline.
Isoquinoline and quinoline are benzopyridines, which are composed of a benzene ring fused to a pyridine ring.

In a broader sense, the term isoquinoline is used to make reference to isoquinoline derivatives.
1-Benzylisoquinoline is the structural backbone in naturally occurring alkaloids including papaverine.
The isoquinoline ring in these natural compound derives from the aromatic amino acid tyrosine.

Isoquinoline is an analog of pyridine.
Isoquinoline structural-based alkaloids, such as tropoloisoquinoline, phthalideisoquinoline, and naphthylisoquinoline has anti-cancer activities.
Isoquinoline, also known as benzo[c]pyridine or 2-benzanine, is a heterocyclic aromatic organic compound.

Isoquinoline is a structural isomer of quinoline.
Isoquinoline and quinoline are benzopyridines, which are composed of a benzene ring fused to a pyridine ring.

In a broader sense, the term isoquinoline is used to make reference to isoquinoline derivatives.
Isoquinoline is the structural backbone in naturally occurring alkaloids including papaverine and morphine.
The isoquinoline ring in these natural compound derives from the aromatic amino acid tyrosine.

Isoquinoline is an aromatic organic chemical compound, which is a structural isomer of quinoline.
Isoquinoline is also known as leucoline.
The structure of isoquinoline consists of a pyridine ring fused to a benzene ring.

Isoquinoline is a colorless liquid with an unpleasant odor.
Isoquinoline is a weak base which protonates to form salts when treated with strong acids.
Isoquinoline is a colorless or slightly yellow oily liquid in appearance.

SYNTHESIS
Isoquinoline was first obtained from coal tar by Hoogewerf and Van Dorp in 1985.
They were able to isolate isoquinoline through fractional crystallization of acid sulfate.
In 1914, Weissgerber devised a better approach to selectively extract isoquinoline from coal tar.

There are numerous methods, through which isoquinoline derivatives can be synthesized.
The Pomeranz-Fritsch reaction is an efficient method for the synthesis of isoquinoline chemical.
Similarly, using glyoxal acetal and benzylamine along with Schlittler-Muller modification, the same results can be obtained.

APPLICATIONS
Isoquinoline is widely used for the preparation of vanilla spice.
This aromatic compound finds applications in the pharmaceutical industry such as the manufacture of drugs for the treatment and prevention of schistosomiasis and malaria.
They are also used as solvents for the extraction of terpenes and resins.

The derivatives of isoquinoline are used as:
*anesthetics
*antihypertension agents
*antifungal agents
*rubber accelerators
*color film sensitizing agents
*topical antiseptics
*drugs
*gas chromatographic stationary liquids
*analytical reagents
*corrosion inhibitors
*disinfectants
*vasodilators

Isoquinolines are used in the production of paints, dyes, fungicides and insecticides.
Pyridine carboxylic acid and its derivatives are synthesized from isoquinoline through oxidation, which is used in the manufacture of dyes and color films.
In the benzoylation reaction and olefin polymerization process, isoquinoline can act as a catalyst.
This aromatic organic chemical compound is used in the qualitative determination of noble metals and the quantitative determination of cadmium and nickel.

SCOPE
Isoquinoline is an important precursor for the discovery of chemicals and drugs.
Numerous synthetic methodologies are constantly being developed with unspecialized chemicals.
The diversity of isoquinoline motifs have greatly expanded with the recent efforts in the synthetic field.

Isoquinoline components are found in many medicinally and agriculturally important bioactive products as well as industrially impactful materials.
• Isoquinoline consists of a benzene ring fused to the β- and ϒ-positions of a pyridine ring.
• Isoquinoline Occurs in coal-tar and bone oil
• Isoquinoline is also found as part of the total structure of a number of alkaloids e.g., papaverine and morphine.
• Isoquinoline is one of the very few heterocyclic compounds in which numbering of the ring atoms does not start on the hetero atom.

Physical properties of Isoquinoline:
•Isoquinoline is a colorless solid
•Smell like that of benzaldehyde (Almond like).
•Isoquinoline is sparingly soluble in water, and is soluble in many organic solvents.
•Isoquinoline turns yellow on normal storage.

Chemical properties of Isoquinoline:
Isoquinoline resembles quinoline in most of its chemical properties.

1. Basic Character:
•Isoquinoline is a stronger base than quinoline.
Isoquinoline forms stable salts with acids.
2. Electrophilic Substitution:
•Like quinoline, it undergoes electrophilic substitution at C-5 and C-8.
3. Nucleophilic Substitution:
•Isoquinoline undergoes nucleophilic substitution at C-1 or C-3 if C-1 is occupied.
4. Reduction:
*Mild Reduction: Mild reduction of isoquinoline with tin and hydrochloric acid yields 1,2,3,4-tetrahydroisoquinoIine
*Catalytic Reduction: Reduction with hydrogen and platinum catalyst produces decahydroisoquinoline
5. Oxidation:
•Oxidation with peracetic acid gives the N-oxide.
*Isoquinoline is also oxidized by alkaline potassium permanganate to give pyridine-3,4-dicarboxylic acid (Cinchomeronic acid).

Isoquinoline, also known as 2-benzazine, belongs to the class of organic compounds known as isoquinolines and derivatives.
Isoquinoline is a heterocyclic aromatic organic compound.
Isoquinoline is a structural isomer of quinoline.

Alternative Classes:
-Pyridines and derivatives
-Benzenoids
-Heteroaromatic compounds
-Azacyclic compounds
-Organopnictogen compounds
-Organonitrogen compounds
-Hydrocarbon derivatives

Isoquinoline and quinoline are benzopyridines, which are composed of a benzene ring fused to a pyridine ring.
Isoquinoline is a weak basic compound (based on its pKa).
Being an analog of pyridine, isoquinoline is a weak base, with a pKb of 8.6.

Isoquinoline protonates to form salts upon treatment with strong acids, such as HCl.
Isoquinoline forms adducts with Lewis acids, such as BF3.
Isoquinoline is a colorless hygroscopic liquid at room temperature with a penetrating, unpleasant odor.

Impure samples can appear brownish, as is typical for nitrogen heterocycles.
Isoquinoline crystallizes as platelets that poorly soluble in water but dissolve well in organic solvents such as ethanol, acetone, and diethyl ether.
Isoquinoline is also soluble in diluted acids, due to the formation of the protonated salt derivative.

1-Benzylisoquinoline is the structural backbone in naturally occurring alkaloids including papaverine and morphine.
The isoquinoline ring in these natural compounds derives from the aromatic amino acid tyrosine.
Isoquinoline Belongs to the class of organic compounds known as isoquinolines and derivatives. These are aromatic polycyclic compounds containing an isoquinoline moiety, which consists of a benzene ring fused to a pyridine ring and forming benzo[c]pyridine.

Substituents:
-Isoquinoline
-Benzenoid
-Pyridine
-Heteroaromatic compound
-Azacycle
-Organic nitrogen compound
-Organopnictogen compound
-Hydrocarbon derivative
-Organonitrogen compound
-Aromatic heteropolycyclic compound

Isoquinoline is a structural isomer of quinolone.
This means both these compounds have the same chemical formula but different connectivity of atoms.
Specifically, the position of the nitrogen atom in the ring structure is different in two compounds.

What is Isoquinoline?
Isoquinoline is an isomer of quinolone having the chemical formula C9H7N.
Isoquinoline also occurs as an oily liquid which is highly hygroscopic.
Isoquinoline has a strong and unpleasant odour.
The liquid can turn in to a yellow or brown colour due to the presence of impurities.
Upon crystallization, this compound crystallizes as platelets.
These platelets have low water solubility, but they dissolve in organic solvents such as:
-ether
-ethanol
-acetone
-diethyl ether
-carbon disulfide, etc.

Isoquinoline is also soluble in some dilute acids.
First, isoquinoline was extracted from coal tar, via fractional distillation.
Isoquinoline is more basic than its structural isomer quinolone.
Isoquinoline is due to the difference in the position of the nitrogen atom in these structures.
Due to this basic property, we can obtain isoquinoline from coal tar via fractional distillation.

There are many important applications of isoquinoline:
-as an anaesthetic compound,
-as antihypertension agents,
-as antifungal agents,
-as disinfectants,
-as vasodilators, etc

What is the Difference Between Quinoline and Isoquinoline?
Quinolone and isoquinoline are isomers of each other.
These structures form via the combination of a benzene ring and a pyridine ring.
The key difference between quinoline and isoquinoline is that in quinolone, the nitrogen atom is in the first position of the ring structure, whereas in isoquinoline, the nitrogen atom is in the second position of the ring structure.

There are many applications of quinoline, such as in the manufacturing of dyes, as a solvent for resins and terpenes, as a precursor to producing 8-hydroxyquinoline, production of quinolinic acid, production of anti-malarial derivatives, etc.
The applications of isoquinoline include using it as an anaesthetic compound, as antihypertension agents, as antifungal agents, as disinfectants, as vasodilators, etc.

PHYSICAL PROPERTIES OF ISOQUINOLINE:

-Molecular Weight: 129.16

-Exact Mass: 129.057849228

-Monoisotopic Mass: 129.057849228

-Topological Polar Surface Area: 12.9 Å²

-Physical Description: Colourless liquid, hygroscopic platelets when solid; Heavy-sweet balsamic, herbaceous aroma

-Color: colorless

-Form: liquid

-Taste: Heavy-sweet balsamic, herbaceous aroma

-Boiling Point: 243.2 °C

-Melting Point: 26.47 °C

-Solubility: 4.52 mg/mL

-Density: 1.097-1.103

-Vapor Pressure: 0.07 mmHg

-LogP: 2.08

-LogS: -1.45

-Atmospheric OH Rate Constant: 8.50e-12 cm3/molecule*sec

-Refractive Index: 1.621-1.627

-pKa: 5.42

CHEMICAL PROPERTIES OF ISOQUINOLINE:

-Heavy Atom Count: 10

-Formal Charge: 0

-Complexity: 111

-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

-XLogP3: 2.1

-Hydrogen Bond Donor Count: 0

-Hydrogen Bond Acceptor Count: 1

-Rotatable Bond Count: 0

SYNONYMS:

2-Azanaphthalene
2-Benzazine
Benzo[c]pyridine
Isochinolin
beta-Quinoline
Benzo(c)pyridine
2-Benzanine
3,4-Benzopyridine
.beta.-Quinoline
Isochinolin [Czech]
isoquinolin
beta -quinoline
Isoquinoline, 97%
Isoquinoline, technical grade, 90-92%
8-(1,4-diazepan-1-ylsulfonyl)isoquinoline
2-benzazine
2-Benzazine
Benzo[c]pyridine
Isochinolin