SU369793A1 - - Google Patents

Description

one

The invention of the preparation of substituted indandions, namely hydrochloride-2-methylamino2-ethnindanedione-1, 3, which can be used in the pharmaceutical industry.

A method of producing hydrochloride-2-methylamino-2-ethyldinanedione-1, 3 is known, which consists in that 2-bromo-2-ethylindanedion-1,3 is reacted with methylamine in benzene medium to release the target product from the reaction medium with salt treatment acid, followed by precipitation of the base with aqueous ammonia and saturation with dry hydrogen chloride.

The yield of the target product is very low (7.5%).

The proposed method for the preparation of hydrochloride-2-methylamino-2-ethyldinanedione-1, 3 is that 2-bromo-2-ethylindanedion1, 3 is reacted with methylamine in benzene with the addition of an aprotic polar solvent, preferably dimethylformamide or dimethyl sulfoxide, with isolating the target product from the reaction medium by extracting 3–15% hydrochloric acid, followed by precipitating the base of 2-methylamino-2-ethyldinanedione-1,3 with aqueous ammonia and turning it into a hydrochloride with a known method. The yield of the target product is 16%.

The proposed method makes it possible to increase the yield by more than two times; moreover, it is simpler to perform, since using it does not require saturation of the reaction mass with hydrogen chloride to isolate the hydrochloride or 2-methylamino-2-ethylandanedione-1, 3 oxalate.

Example 1. Hydrochloride-2-methylamino-2-ethylindic-1, 3.

To 600 ml of benzene solution of 2-bromoethylindandione-1,3, which is obtained from propylidenephthalide (synthesized, using 148 g of 1. Mole of phthalic anhydride), after separation of calcium chloride, add

140-200 ml of dimethylformamide or dimethyl sulfoxide and then immediately saturated with 31.8 g of dry methane laminate at a mass temperature of about 10 ° C in terms of weight gain. The required amount of methylamine is calculated from the consumption of bromine during bromination, considering that per mole of bromide (253 g), 2 mol (62 g) of methylamine must be introduced into the reaction. The flask is closed and left at room temperature (the reaction mass is dark red), methylamine hydrobromide precipitates and the contents of the flask are slightly heated. The next day, but the process is known. Output 36 g (15.0% of theoretical, counted on phthalic anhydride) of a white crystalline substance with t. 226-228 ° C (from absolute ethanol with the addition of ether or petroleum ether).

Example 2. Hydrochloride-2-methylamio-2 ethylindandi-1, 3.

The reaction of 2-bromo-2-etilindandio 1a-1,3 with methylamine is carried out as in Example 1. The next day, methylamine hydrobromide is separated and the filtrate is washed with 2-3 ml of water 350 ml. The organic portion is extracted 2 times with diluted hydrochloric acid (1: 4), using only 350 ml of dilute hydrochloric acid. The acidic extracts are combined and slowly brought to pH 8-9 by adding about 65 ml of 25% aqueous ammonia while cooling with ice water. The precipitate is separated after 2-3 hours, washed with water. The yield of the base after drying is from 38 to 42 g (a yellow substance with a melting point of 102-104 ° C). The substance is dissolved in 350 ml of benzene and hydrogen chloride gas is passed into the solution until a precipitate forms, after 1-2 hours the salt is separated, yield 37-41 g (15.4-17.1% of theoretical, considering phthalic anhydride) ; white crystalline

substance with t. dec. 226-228 ° C after crystallization from absolute ethanol with the addition of ether or petroleum ether.

N 5.92; C1

Found,%: C 60.21; H 5.75; 14.90. N 5.84: C1

Calculated,%: C 60.13; H 5.88: 14.80.

Subject invention

Claims (2)

1. A method of obtaining hydrochloride-2-methylamino-2-ethylindanedione-1, 3 by reacting 2-bromo-2-ethylindanedione-1,3 with methylamine in benzene medium, extracting the target product from the reaction mass by extraction with 3-15% hydrochloric acids, followed by precipitation of the base of 2-methylamine-2-ethylindanedione-1, 3 with aqueous ammonia and its conversion into a hydrochloride, characterized in that, in order to increase the yield of the product, the process is carried out with the addition of an aprotic polar solvent. 2. A method according to claim 1, characterized in that dimethylformamide or dimethyl sulfoxide is used as an aprotic polar solvent.