The Production Process of 8-Methyl-4(3H)-quinazolinone

Introduction
In the chemical industry, the production process of various chemicals is a critical factor in determining their quality and cost.
8-methyl-4(3H)-quinazolinone is an organic compound that is widely used in the pharmaceutical, agrochemical, and dye industries.
This article provides a detailed overview of the production process of 8-methyl-4(3H)-quinazolinone, including the raw materials, the manufacturing steps, and the quality control measures.

Raw Materials
The production of 8-methyl-4(3H)-quinazolinone requires a range of raw materials, including aniline, oxalic acid, and formaldehyde.
Aniline is an aromatic amine that is derived from the reaction of aniline hydrochloride with sodium hydroxide.
Oxalic acid is a carboxylic acid that is produced by the oxidation of crushed coal or by the hydrolysis of succinic acid.
Formaldehyde is a colorless gas that is produced by the electrolysis of water or by the oxidation of methanol.
The quality of the raw materials used in the production of 8-methyl-4(3H)-quinazolinone is critical to the quality of the final product.

Manufacturing Steps
The production of 8-methyl-4(3H)-quinazolinone involves several steps, including the synthesis of the intermediate compound, the oxidation of the intermediate compound, and the purification of the final product.

Synthesis of Intermediate Compound
The synthesis of the intermediate compound involves the reaction of aniline and oxalic acid in the presence of an acid catalyst.
The reaction takes place in a reaction vessel, and the mixture is heated to a temperature of approximately 150-170°C.
The reaction is exothermic, and the temperature must be carefully controlled to prevent overheating.
The product is then neutralized with sodium hydroxide, and the resulting mixture is extracted with water and ethyl acetate.
The organic layer is dried over anhydrous sodium sulfate and then filtered.
The filtrate is concentrated under reduced pressure to obtain the intermediate compound.

Oxidation of Intermediate Compound
The oxidation of the intermediate compound involves the reaction of the intermediate compound with formaldehyde in the presence of a catalyst, such as sulfuric acid.
The reaction takes place in a reaction vessel, and the mixture is heated to a temperature of approximately 60-80°C.
The reaction is exothermic, and the temperature must be carefully controlled to prevent overheating.
The product is then neutralized with sodium hydroxide, and the resulting mixture is extracted with water and ethyl acetate.
The organic layer is dried over anhydrous sodium sulfate and then filtered.
The filtrate is concentrated under reduced pressure to obtain the final product, 8-methyl-4(3H)-quinazolinone.

Purification of Final Product
The final product, 8-methyl-4(3H)-quinazolinone, contains impurities, such as aniline and formaldehyde, that must be removed to obtain a pure product.
The purification of the final product involves several steps, including the crystallization, the recrystallization, and the chromatography.

Crystallization
The final product is dissolved in a solvent, such as ethanol or ether, and then allowed to crystallize.
The crystals are collected by filtration and then washed with water and ethanol.
The crystals are then dried under vacuum to obtain a purified product.

Recrystallization
The purified product is dissolved in a solvent, such as ethanol or ether, and then