O-Phthalimide
[CAS# 85-41-6]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyrimidine compound >> Methyl pyrimidine
• Name: O-Phthalimide
• Synonyms: Phthalic dicarboximide; Phthalimide; Isoindole-1,3-dione
• Molecular Formula: C₈H₅NO₂
• Molecular Weight: 147.13
• CAS Registry Number: 85-41-6
• EC Number: 201-603-3
• SMILES: C1=CC=C2C(=C1)C(=O)NC2=O

Properties

• Density: 1.21 g/mL
• Melting point: 233.5-235 °C
• Sublimation: 366 °C
• Boiling point: 366 °C
• Flash point: 165 °C
• Water solubility: <0.1 g/100 mL at 19.5 °C

Safety Data

• Safety Statements: S24/25

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2A	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

O-phthalimide, also known as phthalimide, is a cyclic imide derived from phthalic anhydride. It was first synthesized by the German chemist August Kekulé in the mid-19th century. The compound has gained fame due to its stability and versatility in chemical reactions and has found widespread applications in organic chemistry.

Phthalimide is a key intermediate in organic synthesis. It is commonly used in the Gabriel synthesis to prepare primary amines. In this reaction, phthalimide is converted to potassium phthalimide, which then reacts with alkyl halides to form N-alkylphthalimides. These intermediates hydrolyze to produce primary amines, which are building blocks for the synthesis of pharmaceuticals, agrochemicals, and other organic compounds.

In the pharmaceutical industry, phthalimide derivatives are used in the development of drugs and medicinal compounds. A notable example is thalidomide, which, despite its notorious history, has found new applications in the treatment of certain cancers and autoimmune diseases. Other phthalimide-based drugs are being investigated for the treatment of various diseases.

Phthalimide is also used in the production of polymers. It acts as a monomer or co-monomer in the synthesis of polyimides, a class of high-performance polymers known for their thermal stability, mechanical strength, and chemical resistance. These materials are used in aerospace, electronics, and other demanding applications where durability and performance are critical.

In the agrochemical industry, phthalimide is an intermediate in the synthesis of pesticides and herbicides. Its derivatives are used to make compounds that protect crops from pests and diseases, thereby increasing agricultural productivity and sustainability.

Phthalimide remains an important compound in research and development. Scientists explore its reactivity and potential applications in the creation of new materials, drugs, and chemical processes. Its role in the synthesis of heterocyclic compounds and other complex molecules makes it a valuable tool in chemical research.

References

2024. Merging photoredox with metalloenzymatic catalysis for enantioselective decarboxylative C(sp3)‒N3 and C(sp3)‒SCN bond formation. Nature Catalysis, 7(12).
DOI: 10.1038/s41929-024-01257-7

2024. Gabriel-Synthese. Namensreaktionen.
DOI: 10.1007/978-3-031-52850-7_56

2015. Structure-based design of phthalimide derivatives as potential cyclooxygenase-2 (COX-2) inhibitors: Anti-inflammatory and analgesic activities. European Journal of Medicinal Chemistry, 92.
DOI: 10.1016/j.ejmech.2014.12.039