SU696017A1 - Method of preparing 9-methylcarbazolylacetic acids - Google Patents

Description

(54) METHOD OF OBTAINING 9-ME.TILKARBAZODUSOXIDE

ACID

The invention relates to the improvement of the process for the preparation of .9-methylcarbazolyl acetic acids, which are the initial half-products of the synthesis of heat-resistant high-molecular materials, and can also be used as intermediate products in the synthesis of biologically active substances. A known method for producing 9-methylcarbazolyl-3-acetic or 3,6-diacetic acids by omination of 3-acetamide or 3,6-diacetamide-9-alkyl carbazoles 1 ... .. The disadvantage of this method is with multistage, since Adetamides are prepared from 9-methyl-3-. -acetyl- (3,6-diacetyl) -carbazoles, which in turn are derived from 9-methylcarbazole 2. The purpose of the present invention is to simplify the process for the preparation of 9-methyl arba olylacetic acids. This goal is achieved using the method of preparing 9-methyl carbazolyl acetic acids of the general formula. CHjCOOH consists in the fact that 9-methyl-3-ethoxalyl- (or 3,6-dystokealyl) -carbazole is reduced by simultaneous hydrolysis of gt with drazine hydrate in ethylene glycol in the presence of an alkali metal hydroxide with heating for 2 hours at a temperature of 135-140 in the subsequent temperature increase up to 190-195 ° С. Despite the fact that the starting products of this method also need to be previously obtained from 9-methylcarbazole, this method is much simpler than the known one. Example 1. 9-Methylcarbazolyl-3-acetic acid. To a solution of 21 g (0.075 M) of 9-methyl-Z-ztoxalylcarbazole and 11.25 g (0.225 M) of hydrazine hydrate in 70 ml of ethylene glycol, 21 g (0.375 M) of finely divided potassium hydroxide is added. The mixture is heated under reflux to 135-140 ° C and kept at this

temperature 2 hours The reflux was cooled and the temperature was raised to 190-195 ° C and kept at this temperature for another 2 hours. The reaction cMRCb was cooled and acidified with hydrochloric acid to. The precipitate formed is filtered and dissolved in 800 ml of an 8% solution of hydrogencarbonate sodium. Filtered, acidified with dilute hydrochloric acid (1: 1) to. The precipitate formed is filtered, dried at a temperature and recrystallized from toluene to give 14.2 g (30% a) pure product. : Mp from 164 to 165 ° C.

Found,%: C 74.8; L 5.43; N 5.78

Ci5 13 NOi

c 75.3; ri 5.48;

Calculated,%;

N 5.85.

IR Spector, 3600-3200;

2970-2860; 1710

Example 2.9-methylcarbazolyl-3, 6-Dyukeic acid. To a solution of 38.1 g (0.1 M) of 9-methyl-3,6-diethoxalylcarbazole and DOR, (0.6 M) hydrazine hydrate in 150 ml of ethylene glycol are added 56 g (1 M a) finely divided potassium hydroxide. The mixture is heated with a reflux condenser to 135-140 ° C and held in a shot at an et temperature of 2 hours. Return to the oven and heat and heat to 19 ° -195 ° C and keep at this temperature for another 2 hours. The reaction mixture is cooled and diluted 500 ml of water n is acidified with hydrochloric acid to. OSZ; the dock is filtered and dissolved in 600 ml of 4% sodium hydrogencarboate solution. Filtered and reproached

diluted hydrochloric acid (1: 1).

The precipitate formed is filtered, dried and, after recrystallization from glacial acetic acid, 22.8 g (77%) of 9-methylcarbazolyl-3, 6-diacetic acid are obtained.

Found,%: C67.6; H4.93; N 4.45

 04

Calculated,%: C 68.7; H 5.08;

N 4.71 IR Spector, 3600-3200;

3000-2900;

1730

Claims (1)

Invention Formula The method of obtaining 9-methylcarbazolyl acetic acids of the general formula where 25 In order to simplify the process, 9-methyl-3-ethoxalylcarbazole or 9-methyl-3, 6-diethoxalylcarbazole is reduced with simultaneous hydrolysis with hydrazine hydrate in ethylene glycol in the presence of alkali hydroxide metal at a temperature of 135-140 0 e pbsleduled by raising the temperature to 19p-195s. 35 sources of information1) taken into account during the examination 1. Collection of ores of young scientists,. Tomsk Polytechnic Institute, 1973, SP.1., P. 186-189. 402. RZHHim, 19 Zh254, 1973.