SU134258A1 - The method of obtaining n-nitrophenylaminoethanol - Google Patents

Description

L-nitrophenylaminoethanol, which is one of the intermediates in the industrial synthesis of synthomycin, is currently produced by reacting p-nitrophenyl chloromethyl carbinol with a water-methanol solution of ammonia according to the scheme:

O2NsbN4 SNON. СНаС + ЫНз-О2МСбН4 СНН. CHaNH

A significant disadvantage of this method of producing nitrophenylaminoethanol is the formation of by-products and resins. As a result, the yield of the target product does not exceed 60% of the theory, based on the initial, carbinol.

A new method of p-nitrophenylaminoethanol production from p-nitrophenyl chloromethyl carbinol or from rt-nitrostyrene oxide was found, which consists in that, in order to increase the yield, simplify the process and reduce the volume of the equipment used, the amination is carried out by heating in excess liquid ammonia under pressure in the presence of water.

When carrying out the relevant experimental work, it was established that:

1. Liquid ammonia serves as a good solvent of p-nitrophenyl chloromethyl carbinol and nitrostyrene oxide, and therefore the use of methanol as a solvent is excessive.

2. When aminating with liquid ammonia p-nitrophenyl chloromethyl carbinol and p-nitrostyrene oxide, the presence of water is required, because in the absence of water, carbinol is converted to nitrostyrene oxide, which does not form aminoethanol in the absence of water.

Example 1. A steel autoclave with a capacity of 1 l, equipped with a thermometer sleeve and the corresponding fittings, was charged with 20.2 g of p-nitrophenyl chloromethylcarbnol and 200 ml of ammonia water. The autoclave is closed, 460-500 mm of liquid ammonia is loaded into it from a measuring device, heated to 50-55 ° with a thermometer in a sleeve, placed in a rocking chair and moved at this temperature for 1 hour, while the pressure rises to 15 atm. Then excess ammonia

No. 134258- 2 is slowly lowered into the brine cooled to -20 ° a measuring device for liquid ammonia. When the pressure in the autoclave and the dipstick is equal, the autoclave is heated to 80 ° and ammonia is completely distilled off within 25-30 minutes. The autoclave is cooled and the reaction mass, which is a suspension of aminoethanol crystals in ammonia water, is filtered off, washed with water and dried at 80 °. 15,, 0 g -nitrophenylaminoethanol is obtained with a melting point, which constitutes a yield of 85-88% of theory, based on the initial carbinol.

Example 2. In the autoclave described in example 1, load 33 g of oxide, l-nitrostyrene, 200 ml of ammonia water and 500 ml of liquid ammonia. The aminating process is carried out as in Example 1, but heating at 50-55 ° is carried out for one and a half hours. Obtain 32.5-33.5 g of dry β-diprophenylaminoethanol with m.p. 133-136 °, which is a yield of 90-92% of theory, based on the starting nitrostyrene oxide.

Since during the described operations there are no side reactions and gum formation, there is no need for settling tanks currently used, and the capacity of the autoclave at the same power can be significantly reduced.

Subject invention

The way of crawling -nitrophenylaminoethanol from -nitrophenyl chloromethyl carbinol or l-nitrostyrene oxide, characterized in that ammonolysis is carried out by heating in excess liquid ammonia under pressure in the presence of water to increase output, simplify the process and reduce the amount of equipment used.