SU126111A1 - The method of obtaining n-nitrobenzoylchloroethanol - Google Patents

Description

There are known methods for the preparation of / g-nitrobenzoyl chloroethanol, for example, by reacting ethylene chlorine: drin: with parabenzoic benzoyl chloride or esterifying l-nitrobenzoic acid with ethylene chlorohydrin in the presence of sulfuric acid. However, using these methods, expensive reagents are used.,.

The proposed method for the preparation of -nitrobenzoyl chloroethanol makes it possible to substantially reduce the cost of production. The method consists in the interaction of β-pyrobenzoate diethylammonium with dichloroethane. This reaction is carried out through the use of sodium iodide as a catalyst.

Example 1. In an apparatus with reflux condenser and heating (water in a bath) is charged: 50 kg of dichloroethane, 8.4 kg of p-nitrobenzoic acid, 3.6 kg of diethylamine, 0.2 kg of sodium iodide.

All downloadable substances must not contain moisture. The mixture is refluxed for 24-32 hours. In this case, first everything goes into solution. Then, as the reaction proceeds, the solution darkens and crystals of hydrochloric acid diethylamine are extracted from it.

Upon cooling, the reaction mixture is poured into a crystallizer cooled with ice water or ice. The salts of diethylamine crystallized on cooling (ha-nitrobenzoic and hydrochloric acids) are sucked off, washed with dichloroethane and stored in a closed jar. The dichloroethane solution is treated in a separating funnel with warm water 3 times 10 liters to wash off the residue of diethylamine salts, then 2 times 5 liters of 10% hydrochloric acid to remove basic products, then 10 liters of pure water.

The dichloroethane solution is carefully separated from the aqueous layer, dried with calcium chloride and evaporated until the last traces of dichloroethane have disappeared by blowing air. The remaining oil is at

No. Imm- 2 -.

by cooling and seeding with a crystalline substance, the substance crystallizes1 into a continuous crystalline mass “-nitrobenzoylchloroethanol of technical grade. Yield 6-7 kg or 50-75% of theoretical, based on the initial nitrobenzoic acid.

After recrystallization from 70% alcohol, slightly colourant crystals are obtained with a mp. 52-53 °.

Post-extraction aqueous solutions containing diethylamine salts are treated as indicated in Example 2.

Example 2. Dichloroethane is completely distilled off from the reaction mixture obtained by the method described in Example 1. The remaining oil is washed with hot water (50-60 °) by decantation until the sample ceases to precipitate with hydrochloric acid (nitrobenzoic acid).

All salts of diethylamine are transferred to hot water. The oil is then washed with this method 2 times with 5% hydrochloric acid and once with pure water. After washing, the oil is cooled and crystallized with a seed of a l-nitrobenzoyl chloroethanol crystal.

Diethylamine Salt Regeneration

Aqueous extracts (as in example 1 or 2) are collected together, averaged with a certain amount of nitrobenzoic acid and evaporated in an open bowl in a water bath to a small volume. The salt of diethylamine and nitrobenzoic which crystallized on cooling. the acids are sucked off, dried and used again for condensation. The aqueous mother liquor, which contains most of the hydrochloric acid diethylamine, is treated with a saturated solution of the nitrobenzoic acid sodium salt. The niphobenzoic acid diethylammonium salt which precipitated in this process is filtered off with suction, dried and reintroduced.

Subject invention

A method of producing p-nitrobenzoyl chloroethanol, characterized in that, in order to expand the raw material base and reduce the cost of the process, p-nitrobenzoic acid dialkylammonium salts are heated with dichloroethane in the presence of sodium iodide as a catalyst.