PHTHALIMIDE

Phthalimide is a versatile nitrogen-containing intermediate widely used in pharmaceutical, agrochemical, and specialty chemical synthesis.
Phthalimide's stable cyclic imide structure and useful reactivity make it an important building block for preparing primary amines and other functional organic compounds.
With broad applicability in controlled synthesis pathways, phthalimide supports efficient and reliable downstream chemical transformations.

CAS Number: 85-41-6
EC Number: 201-603-3
Molecular Formula: C8H5NO2
Molecular Weight: 147.13

Synonyms: PHTHALIMIDE, 85-41-6, Isoindole-1,3-dione, 1H-Isoindole-1,3(2H)-dione, o-Phthalic imide, Benzoimide, 1,3-Isoindolinedione, 2-Diazoindan-1,3-dione, Phenylimide, Phthalimid, 1,2-Benzenedicarboximide, Ftalimmide, DTXSID3026514, 1J6PQ7YI80, NSC-3108, DTXCID506514, CHEBI:38817, RefChem:6138, 201-603-3, 621-254-4, isoindoline-1,3-dione, O-Phthalimide, 2,3-dihydro-1H-isoindole-1,3-dione, phtalimide, 1,3-Dihydroisoindole-1,3-dione, NSC 3108, 1,3-Isoindoledione, Epinastine Impurity 17, MFCD00005881, 223537-84-6, Phthalimid [German], Ftalimmide [Italian], 2H-benzo[c]azoline-1,3-dione, CAS-85-41-6, 136918-14-4, Phthalic dicarboximide, Phthalimide; Tafenoquine related; SKF-2450, HSDB 5007, 1,3-Dihydro-1,3-dioxoisoindole, EINECS 201-603-3, BRN 0118522, isoindoledione, UNII-1J6PQ7YI80, Pthalimide, phthalimide-, AI3-07565, CCRIS 9479, hydroxyisoindolone, folpet TP1, hydroxy isoindolone, 1,3-dioxoisoindole, isoindol-1,3-dione, 1,3-Dihydro-2H-isoindole-1,3-dione, isoindoline-1,3 dione, Phthalimide, >=99%, 3-hydroxyisoindol-1-one, SCHEMBL64, isoindoline -1,3-dione, PHTHALIMIDE [MI], 1h-isoindole-1,3-dione, PHTHALIC ACID,IMIDE, EC 201-603-3, WLN: T56 BVMVJ, isoindole-1,3(2H)-dione, SCHEMBL19888, 5-21-10-00270 (Beilstein Handbook Reference), SCHEMBL132473, SCHEMBL156695, SCHEMBL606038, 1H-isoindole-1,3(2H)dione, 3-Hydroxy-1H-isoindol-1-one, CHEMBL277294, SCHEMBL1388700, SCHEMBL3098639, SCHEMBL3771399, SCHEMBL3793048, SCHEMBL3793049, 1H-isoindole-1,3(2H) dione, SCHEMBL29366030, 1H-isoindol-1,3-(2H)-dione, NSC3108, 1H-isoindole-1,3-(2H)-dione, Tox21_201800, Tox21_303319, BBL037023, BDBM50350644, SBB059859, STK299439, 2,3-dihydro-1H-isoindole-1,3-dion, AKOS000119824, EBC-151075, FP31525, FS-3820, NCGC00249121-01, NCGC00249121-02, NCGC00257137-01, NCGC00259349-01, Phthalimide, puriss., >=99.0% (T), DS-002743, phthalimide [1h-isoindole-1,3(2h)-dione], NS00010682, P0402, ST45061499, EN300-17966, Phthalimide, PESTANAL(R), analytical standard, AP-770/40217754, F358204, Q412784, Z57127356, F9995-1638, Phthalic dicarboximide; Phthalimide; Isoindole-1,3-dione, InChI=1/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11, 1,3-Dihydro-1,3-dioxoisoindole, 118522, 1H-Isoindol-1,3(2H)-dion, 1H-Isoindol-1-one, 3-hydroxy-, 1H-Isoindole-1,3(2H)-dione, 1H-Isoindole-1,3(2H)-dione, 1H-Isoindole-1,3-(2H)-dione, 201-603-3, 85-41-6, Phthalimide, 邻苯二甲酰亚胺, 1, 3-Isoindoledione, 1,2-Benzenedicarboximide, 1,3-Dihydro-2H-isoindole-1,3-dione, 1,3-Isoindoledione, 1,3-Isoindolinedione, 1170556-70-3, 136918-14-4, 1H-Isoindole-1, 3 (2H)-dione, 2,3-dihydro-1H-isoindole-1,3-dione, 2-Diazoindan-1,3-dione, 214-046-6, 269409-73-6, 2H-benzo[c]azolidine-1,3-dione, 2H-benzo[c]azoline-1,3-dione, 5-21-10-00270, 60161-31-1, 99%, Benzene-1,2-dicarboxylic acid imide, Benzoimide, EINECS 201-603-3, Ftalimmide, Glycogen synthase kinase-3 beta, GSK3B_HUMAN, isoindole-1,3-dione, isoindoline-1,3-dione, isoindoline-1,3-quinone, o-Phthalic imide, O-Phthalimide, Phenylimide, phtalimide, Phthalic acid imide, PHTHALIC ACID,IMIDE, Phthalic dicarboximide, Phthalimid, Phthalimid, PhthaliMide--d4, Phthalimide-[15N], Phthalimide-d4, Phthalylimide, T56 BVMVJ

Phthalimide is an organic compound with the chemical formula C8H5O2N.
Phthalimide is a white solid that is slightly soluble in water and soluble in basic solutions.

Phthalimide is acidic, since its conjugate base is resonance stabilised.
Bromine is an electrophile, since Phthalimide is electronegative and bromide is a good leaving group.

Sodium hydroxide is a good base.
The Phthalimide group is the most acidic site and hydroxide is the strongest base.
Bromine is the only electrophile.

Phthalimide is readily deprotonated by hydroxide to give the corresponding anion, this reacts with bromine to give the N-bromophthalimide product.
Gabriel Phthalimide Synthesis is a method of obtaining primary aliphatic amines.
In this reaction phthalimide is converted into its potassium salt by treatment with alcoholic KOH.

Phthalimide is an organic imide compound derived from phthalic anhydride and ammonia, with the molecular formula C8H5NO2.
Phthalimide appears as a white to off-white crystalline solid and contains a cyclic imide group fused to a benzene ring.

Phthalimide is widely used as an intermediate in organic synthesis, particularly in the Gabriel synthesis for preparing primary amines, and as a starting material for pharmaceuticals, agrochemicals, dyes, and specialty chemicals.
Phthalimide's relatively acidic imide hydrogen allows the formation of phthalimide salts, which are useful nucleophiles in substitution reactions.
Phthalimide also serves as a versatile building block in the preparation of nitrogen-containing compounds and functional organic materials.

Phthalimide is the organic compound with the formula C6H4(CO)2NH.
Phthalimide is the imide derivative of phthalic anhydride.

Phthalimide is a sublimable white solid that is slightly soluble in water but more so upon addition of base.
Phthalimide is used as a precursor to other organic compounds as a masked source of ammonia.

Phthalimide is a white to light tan powder.
Phthalimide is a dicarboximide that is 2,3-dihydro-1H-isoindole substituted by oxo groups at positions 1 and 3.

Phthalimide is a reagent used to transform allyl- and alkyl halides into protected primary amines.
Phthalimide is used as a precursor to other organic compounds as a masked source of ammonia.

Phthalimide is engineered for high-performance synthesis workflows and delivers exceptional reliability in demanding industrial processes.
Phthalimide's stable imide structure enables efficient downstream transformations, making Phthalimide a preferred intermediate for pharmaceutical, agrochemical, and specialty chemical applications.

Phthalimide offers consistently high-grade material quality supported by robust manufacturing standards and dependable supply performance.
Phthalimide's consistent quality and versatile reactivity support precise formulation and controlled synthesis processes.

Phthalimide provides B2B users with a reliable building block for a wide range of technical and industrial synthesis applications.
Phthalimide is a reagent used to transform allyl- and alkyl halides into protected primary amines.

Phthalimide is a versatile organic compound widely recognized for its applications in various fields, including pharmaceuticals, agrochemicals, and materials science.
This white crystalline solid, known for its stability and low toxicity, serves as a key intermediate in the synthesis of numerous bioactive molecules.

Researchers often utilize phthalimide in the preparation of pharmaceuticals, particularly in the development of anticonvulsants and anti-inflammatory agents.
Phthalimide's ability to undergo nucleophilic substitution reactions makes it an essential building block in organic synthesis, allowing for the creation of complex molecular architectures.

In addition to its pharmaceutical applications, phthalimide is also employed in the production of dyes, pigments, and polymers, enhancing the performance characteristics of these materials.
Phthalimide's unique properties, such as thermal stability and solubility in organic solvents, make it an attractive choice for industrial applications.
With its broad utility and significant role in advancing chemical research and development, phthalimide continues to be a compound of interest for professionals seeking innovative solutions in their respective fields.

Phthalimide is an organic compound with the chemical formula C8H5O2N.
Phthalimide is a white solid that is slightly soluble in water and soluble in basic solutions

Applications of Phthalimide:
Phthalimide was used in the synthesis of 6-amino agarose (AA) by Mitsunobu-inspired microwave mediated method.

Phthalimide is a reagent used to transform allyl- and alkyl halides into protected primary amines.
Phthalimide is used as a precursor to other organic compounds as a masked source of ammonia.

Phthalimide analogues have been extensively used in medicinal chemistry owing to their wide range of applications as anticonvulsant, antiinflammatory, analgesic, hypolipidemic and immunomodulatory activities.
Number of anti-inflammatory phthalimide analogues have been synthesised as tumor necrosis factor alpha inhibitors.

Phthalimide promotes the inflammatory response leading to many of the clinical problems associated with autoimmune disorders like rheumatoid arthritis, Crohn’s diseases, ankylosing spondylitis, psoriasis and refractory asthma.
Phthalimide is used in the synthesis of indigo and for preparing thiosalicylic acid, which is used in the synthesis of certain indigoid vat dyes.

Uses of Phthalimide:
Phthalimide is used as a raw material in several industries.
Phthalimide is a precursor for the production of anthranilic acid by Hofmann degradation and is used in the Gabriel synthesis to produce a wide range of primary amines.

Phthalimide is used as a protecting group in organic chemistry, particularly peptide synthesis.
By reacting with the amino group, Phthalimide prevents unwanted reactions while the rest of the molecule can be transformed.
Phthalimide can be selectively removed to give the free amine.

Phthalimide is also utilized as an intermediate in the production of agricultural pesticides, wood preservatives, certain pigments, and pharmaceuticals such as Thalidomide, Amphotalide, Taltrimide, Talmetoprim, and Apremilast.

Phthalimide is an imide of commercial and industrial importance, forming a number of interesting derivatives.
With alcoholic potash, phthalimide forms a potassium derivative, C6H4(CO)2NK, which, when reacted with ethyl iodide (or other alkyl halides), yields ethylphthalimide, C6H4(CO)2 N C2H5.

The latter product, when hydrolyzed with an acid or alkali, further yields ethylamine [CAS: 75-04-7] C2H7N.
Such reaction chains are useful in the preparation of certain primary amines and their derivatives.

Phthalimide is a reagent used to transform allyl- and alkyl halides into protected primary amines.
Phthalimide analogues have been extensively used in medicinal chemistry owing to their wide spectrum of applications as anti-convulsant, anti-inflammatory, analgesic, hypolipidimic and immunomodulatory activities.

Phthalimide is used to make dyes, primary amines, amino acids, and Folpet (fungicide).
Phthalimide is also used as a fungicide, laboratory reagent, and inhibitor of oxidation and photochemical reactions.
Phthalimide is used as a precursor to anthranilic acid, a precursor to azo dyes and saccharin.

Alkyl phthalimides are useful precursors to amines in chemical synthesis, especially in peptide synthesis where they are used "to block both hydrogens and avoid racemization of the substrates".

Alkyl halides can be converted to the N-alkylphthalimide:
C6H4(CO)2NH + RX + NaOH → C6H4(CO)2NR + NaX + H2O

The amine is commonly liberated using hydrazine:
C6H4(CO)2NR + N2H4 → C6H4(CO)2N2H2 + RNH2

Alkyl amines can also be used.

Some examples of phthalimide-containing drugs include thalidomide, amphotalide, taltrimide, talmetoprim, and apremilast.
With a trichloromethylthio substituent, a phthalimide-derived fungicide is Folpet.

Industry Uses:
Pigment
Intermediate

Consumer Uses:
Pigment

Features of Phthalimide:
Highly stable imide structure ensures reliable performance in diverse synthesis pathways
Acts as an efficient precursor and masked ammonia source in organic chemistry

Supports broad functionalization, enabling creation of multiple derivative classes
Widely applicable across pharmaceuticals, agrochemicals, dyes, and specialty materials

Niche but essential intermediate with steady global demand and proven industrial relevance
Backed by reliable production processes ensuring consistent product performance
Supported by an established supply framework enabling dependable availability

Reactivity of Phthalimide:
The high acidity of the imido N-H is the result of the pair of flanking electron-withdrawing carbonyl groups.
Both sodium phthalimide and potassium phthalimide are well known.

The latter can be made by reaction of phthalimide with potassium carbonate or potassium hydroxide.
The potassium salt is used in the Gabriel synthesis of primary amines.

Preparation of Phthalimide:
Phthalimide can be prepared by heating phthalic anhydride with alcoholic ammonia giving 95–97% yield.
Alternatively, Phthalimide may be prepared by treating the anhydride with ammonium carbonate or urea.
Phthalimide can also be produced by ammoxidation of o-xylene.

Natural Occurrence of Phthalimide:
Kladnoite is a natural mineral analog of phthalimide.
Phthalimide is very rarely found among a few burning coal fire sites.

Physical Properties of Phthalimide:
Phthalimide is a heterocyclic compound that forms white needles or prisms when crystallized from solution and platelets from sublimation.

Phthalimide has limited solubility in water (0.3 g at 20 °C, 0.9 g at 50 °C, and 2.2 g at 100 °C per 100 g of water).
However, Phthalimide readily dissolves in acetic acid, sodium hydroxide solution, and potassium hydroxide solution.

Phthalimide sublimes when heated above its melting point.
This property makes its purification easier.

Industrial Production:
Phthalimide is primarily synthesized from phthalic anhydride and ammonia, although alternative methods using urea or o-xylene ammoxidation exist.

Production of Phthalimide from Phthalic Anhydride and Ammonia:
Continuous processes are used in industrial-scale phthalimide production.

The vertical reaction tube process uses an externally heated vertical reaction tube filled with packing material.
Molten phthalic anhydride and excess ammonia are continuously fed into the top of the tube and react at 250–280 °C.

The reaction gases are then cooled in a sublimation chamber, where solid phthalimide deposits and is discharged.
Excess ammonia and water are removed through an exhaust gas pipe.
This process yields phthalimide with a purity of 99% and a high yield of 98%.

In the countercurrent process, molten phthalic anhydride is continuously fed to the top of a reactor, while ammonia is continuously fed to the bottom.
The temperature increases gradually from around 150 °C at the top to a maximum of 270 °C at the bottom.

Molten phthalimide with a purity of 99% exits the reactor and is cooled and flaked.
Phthalimide can be dissolved in an aqueous alkali solution for further use.

The exhaust gas from the reactor head, containing water vapor, sublimed phthalimide, and unreacted components, is scrubbed with molten phthalimide from the reactor bottom in a countercurrent fashion.
This scrubbing process purifies the exhaust and allows for the recovery of unreacted starting materials.

Production of Phthalimide from Phthalic Anhydride and Urea:
Phthalimide can be produced from phthalic anhydride and urea in a solvent-free process or in a solvent.

In the solvent-free process, a mixture of phthalic anhydride and urea is heated in a sealed vessel.
The reaction proceeds at 130–140 °C, with carbon dioxide and water vapor as byproduct gases.
The temperature rises to around 160 °C due to the exothermic reaction.

The reaction is completed when the gas evolution ceases.
The solidified reaction mixture is then cooled, ground, and used directly without further purification.
This method offers high yields, exceeding 90%.

In the process using a solvent, the solvent is typically a substituted or unsubstituted hydrocarbon, aromatic compound, or heteroaromatic compound (e.g., n-propylbenzene, cumene, 1,2-dichlorobenzene, picoline).

The solvent needs to be chosen such that urea is insoluble while phthalic acid or anhydride has limited solubility.
The reaction occurs below the solvent’s boiling point (typically 160–170 °C).
After completion, the pure phthalimide product is isolated by filtration and water washing, achieving yields of 95–100%.

Production of Phthalimide from o-Xylene:
While less common than the methods using phthalic anhydride, phthalimide can also be produced from o-xylene.
This process involves reacting o-xylene in the gas phase with ammonia in the presence of a metal oxide catalyst.
This catalyst also acts as an oxygen donor.

Depending on the reaction conditions and control, this process can selectively produce phthalimide, phthalamide, or phthalonitrile.

Stability and Reactivity of Phthalimide:

Chemical stability:
Stable under normal ambient and recommended storage conditions.

Conditions to avoid:
Avoid excessive heat and unnecessary exposure to incompatible materials.

Incompatible materials:
Avoid strong bases and strong oxidizing agents.

Hazardous decomposition products:
Thermal decomposition may generate carbon oxides, nitrogen oxides, and irritating fumes.

Handling and Storage of Phthalimide:

Safe handling:
Avoid generating or inhaling dust and prevent contact with eyes and skin.

Storage conditions:
Keep the container tightly closed in a cool, dry, and well-ventilated area, away from incompatible materials.

First Aid Measures of Phthalimide:

Inhalation:
Move the affected person to fresh air and obtain medical attention if symptoms persist.

Skin contact:
Wash thoroughly with soap and plenty of water and remove contaminated clothing.

Eye contact:
Rinse cautiously with water for several minutes and seek medical attention if irritation continues.

Ingestion:
Rinse mouth with water and obtain medical advice if discomfort develops.

Firefighting Measures of Phthalimide:

Suitable extinguishing media:
Use dry chemical, carbon dioxide, water spray, or suitable foam according to surrounding fire conditions.

Protective equipment:
Firefighters should wear appropriate protective equipment and self-contained breathing apparatus where necessary.

Accidental Release Measures of Phthalimide:

Personal precautions:
Avoid dust formation, provide adequate ventilation, and use suitable protective equipment.

Cleanup methods:
Carefully collect or sweep spilled material into a suitable closed container and clean the affected area thoroughly.

Exposure Controls/Personal Protection of Phthalimide:

Engineering controls:
Provide adequate general or local exhaust ventilation where dust may be generated.

Eye protection:
Wear suitable safety glasses or chemical protective goggles.

Hand protection:
Use appropriate chemical-resistant protective gloves.

Respiratory protection:
Use suitable particulate respiratory protection when ventilation is insufficient or significant dust is generated.

Identifiers of Phthalimide:
CAS: 85-41-6
IUPAC Name: 2,3-dihydro-1H-isoindole-1,3-dione
Molecular Formula: C8H5NO2
InChI Key: XKJCHHZQLQNZHY-UHFFFAOYSA-N
SMILES: O=C1NC(=O)C2=CC=CC=C12
Molecular Weight (g/mol): 147.13

CAS No.: 85-41-6
Chemical Name: Phthalimide
CBNumber: CB1280074
Molecular Formula: C8H5NO2
Molecular Weight: 147.13
MDL Number: MFCD00005881
MOL File: 85-41-6.mol

Product Number: P0402
Purity / Analysis Method: >98.0%(GC)(T)
Molecular Formula / Molecular Weight: C8H5NO2 = 147.13
Physical State (20 deg.C): Solid
Storage Temperature: Room Temperature (Recommended in a cool and dark place, <15°C)
CAS RN: 85-41-6
Reaxys Registry Number: 118522
PubChem Substance ID: 87574609
SDBS (AIST Spectral DB): 1157
Merck Index (14): 7373
MDL Number: MFCD00005881

CAS Number: 85-41-6
ChEBI: CHEBI:38817
ChEMBL: ChEMBL277294
ChemSpider: 6550
ECHA InfoCard: 100.001.458
PubChem CID: 6809
UNII: 1J6PQ7YI80
CompTox Dashboard (EPA): DTXSID3026514
InChI: InChI=1S/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11)
Key: XKJCHHZQLQNZHY-UHFFFAOYSA-N
InChI: InChI=1/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11)
Key: XKJCHHZQLQNZHY-UHFFFAOYAS
SMILES: O=C2c1ccccc1C(=O)N2

Empirical Formula (Hill Notation): C8H5NO2
CAS Number: 85-41-6
Molecular Weight: 147.13
UNSPSC Code: 12352100
NACRES: NA.22
PubChem Substance ID: 24854410
EC Number: 201-603-3
Beilstein/REAXYS Number: 118522
MDL Number: MFCD00005881
Assay: ≥99%

Properties of Phthalimide:
Melting Point: 232-235 °C (lit.)
Boiling Point: 366 °C
Density: 1.21
Vapor Pressure: 0.001 Pa at 25℃
Refractive Index: 1.4700 (estimate)
Flash Point: 165 °C
Storage Temperature: Store below +30°C.
Solubility: water: slightly soluble (lit.)
pKa: 8.3 (at 25℃)
Form: Crystalline Flakes
Color: White to slightly yellow
PH: 3.8 (0.6g/l, H2O)
Water Solubility: <0.1 g/100 mL at 19.5 ºC
Sublimation: 366 ºC
Merck: 14,7373
BRN: 118522
Henry's Law Constant: 9.9×102 mol/(m3Pa) at 25℃, HSDB (2015)
InChI: 1S/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11)
InChIKey: XKJCHHZQLQNZHY-UHFFFAOYSA-N
SMILES: O=C1NC(=O)c2ccccc12
LogP: 1.15
CAS DataBase Reference: 85-41-6 (CAS DataBase Reference)
EWG's Food Scores: 1
FDA UNII: 1J6PQ7YI80
NIST Chemistry Reference: Phthalimide (85-41-6)
EPA Substance Registry System: Phthalimide (85-41-6)
UNSPSC Code: 12352115
NACRES: NA.22

Quality Segment: 200
Assay: ≥99%
Melting Point: 232-235 °C (lit.)
Solubility: water: slightly soluble (lit.)
SMILES String: O=C1NC(=O)c2ccccc12
InChI: 1S/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11)
InChI Key: XKJCHHZQLQNZHY-UHFFFAOYSA-N

Chemical Formula: C8H5NO2
Molar Mass: 147.133 g·mol−1
Appearance: White solid
Melting Point: 238 °C (460 °F; 511 K)
Boiling Point: 336 °C (637 °F; 609 K) sublimes
Solubility in Water: <0.1 g/100 ml (19.5 °C)
Acidity (pKa): 8.3
Basicity (pKb): 5.7
Magnetic Susceptibility (χ): −78.4×10−6 cm3/mol
Related Compounds:
Related Amides: Maleimide
Related Compounds: Phthalic anhydride

Molecular Weight: 147.13 g/mol
XLogP3: 1.1
Hydrogen Bond Donor Count: 1
Hydrogen Bond Acceptor Count: 2
Rotatable Bond Count: 0
Exact Mass: 147.032028402 Da
Monoisotopic Mass: 147.032028402 Da
Topological Polar Surface Area: 46.2 Ų
Heavy Atom Count: 11
Formal Charge: 0
Complexity: 190
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

Specifications of Phthalimide:
Appearance: White to Almost white powder to crystal
Purity (GC): min. 98.0 %
Purity (Neutralization titration): min. 98.0 %
Melting Point: 230.0 to 238.0 °C
Appearance (Color): White to pale cream or pale yellow
Identification (FTIR): Conforms
Form: Crystals or powder or crystalline powder or flakes
Assay (HPLC): ≥98.5%

Names of Phthalimide:

Preferred IUPAC name:
1H-Isoindole-1,3(2H)-dione

Other names:
1,3-Dioxoisoindoline
Phthalimidoyl (deprotonated)