SU334832A1 - METHOD OF OBTAINING HETEROCYCLIC HYDRAZONES - Google Patents

Description

The invention relates to the field of production of nitrogen-containing nitrogen hydrazoic and 1.11 x heterocyclic ketones, which are intermediates for the production of azo dyes.

Many methods for the preparation of hydrazones, including heteronicic ones, are known. One of them is a method for producing hydrazones of heterocyclic oxo compounds of the general formula

.-BUT

C N-NHki

Y

Vg

where l is a hydrocarbon radical, which may contain heteroatoms;

RI is hydrogen, alkyl, aralkyl, etc .;

R2 is an aliphatic, cycloaliphatic radical.

The method consists in the fact that the heterocyclic nmnd of the general formula

where A and R2 are as defined above, and RI is hydrogen or alkyl, they are reacted with hydrapp, substituted alkyl, aralkyl, etc. The products are isolated as usual.

However, with this method, the preparation of the starting α-imino compounds from the corresponding α-amino compounds is difficult due to their low stability and easy hydrolysis ability during isolation to the corresponding ketones. Therefore, although the reaction of the imino compounds with hydrazines proceeds smoothly, the yield of the non-nelevant product to the starting amine remains RED.

In order to simplify the process, a method is proposed for the obtained heterocyclic hydrazoes of the general formula.

20

s- NKIi

or

25 where R is lower alkyl;

X is sulfur, oxygen or a group. The method consists in that the corresponding 2-amino derivative of the heterocycle, for example 2-aminobenzthiazole, is alkylated, as usual, for example with dimethyl sulfate, and the quaternary salt of the general formula | C-Iffij 4 il / v., - H / r.,. y, where R, A, and X are as defined, and Y, anions of an acid, interact with hydrazine. At the same time, a part of the hydrazine used, which is consumed for the orazine-anne salt of hydrazine with methyl sulfuric acid, can be replaced by alkali. It is better to conduct the process at boiling of the reaction mass in the medium of an organic solvent, for example acetone, or, in an aqueous medium, in the presence of a buffer solution at pH 6-8. Alkylate 2-amioheterocycle, preferably in the presence of a surfactant. Products are isolated in a known manner. Example 1. To 60 g of 2-amio-6-methoxybenzthiazole in LOOO ml of acetone, 50 ml of dimethyl sulfate are poured in for 10 min at boiling, the mass is boiled for another 4 hours, cooled while stirring, filtered, the precipitate is washed with acetone and glue. 94.5 g of 3-methyl-6-methoxy-2-aminobenzothiazolium methyl sulfate are obtained with a yield of 92.7%, and the like. 244- 245 ° С (with decomposition). Found,%: N9,22; 9, 30. CioHi4NO5S2. Calculated,%: N 9.15. To 3.3 ml of hydrazine hydrate in 5 ml of water, a solution of 6.12 g of 3-methyl-6-methoxy-2-aminomethylasethiamethylsulfate in 26 ml of water is poured in at boiling for 1 hour, the mixture is boiled for 1 hour, cooled, the precipitate is filtered , washed with water and existing. Obtain 3.8 g of 3-methyl-6-methoxybeistiazolo-2-hydrazone with the release of 84.8% (2-a1Mino-6-methoxybenzthiazole) and so on. Pl. 160-161 ° C (from alcohol). Similarly, 2 ml of hydrazine hydratemide and 5 ml of 20% NaOH in 5 ml of water and 6.12 g of 3-methyl-6-methoxy-2-amino-isobenzothiazolium methyl sulfate. In 26 ml of water, three-methyl-6-methoxy-benzothiazolone-1-2-hydrazone 1 is obtained with the yield 85% (on 2-amino-6-methoxybeistiazol), and so on. 160-161 ° C. Example 2. 0.3 mol of 2-amio-6-methoxy-biistiazol is placed in a mixture of 75 ml of buffer solution (2 g of Na.FbPO.i in 100 ml of water with addition of caustic soda to RP 6.5) and 20 ml of 10 % of the p: solution of butylpaphthalene sulfoate (wetter, NB) for 2 hours at 20–25 ° C, 42.5 ml of dimethyl sulfate are added to the same place, all this is placed for another I hour at the indicated temperature and heated to 80 ° C. In the reaction mass, a pH of about 6 is poured into it dropwise a 40% solution of caustic soda (total consumption of caustic soda about 40 ml. Next, the mass of 10 minutes at 80 ° C, diluted with 500 ml of water, left at room temperature for 12 hours, and filtered. The filtrate is then poured into 4 ml of boiling 50% hydrazine hydrate solution for 4 hours and boiled for another 1 hour. , cooled to 10 ° C, hydrazone precipitate is filtered off by filtration B1, washed with water and existed at 60 ° C. 55.3 g of 3-methyl-6-methoxynbenzthiazolone-2-hydrazone is obtained with a yield of 88.34% and so on. 158- 160 ° C. Example 3. To a solution, py 94 g of 2-aminopyridine in 140 ml of a buffer mixture prepared as above, at 5-10 ° C, irinite for 3.5 hours, 193 ml of dimethyl sulfate, allowing The end temperature is raised to 20 ° C. For 2 hours, the mass is heated to 75 ° C, placed 10 minutes at 75 ° C, cooled to 20 ° C and filtered. During the reaction, the pH is controlled, maintaining it within 6-6.5 by adding a 30% caustic patra solution. The resulting solution of methyl 1-methyl-2-aminopyridini methyl sulfate is poured into the boiling mixture of 200 ml of hydrazihydrate and 200 ml of water for 15 minutes, boiled for 2 hours, evaporated under vacuum in a nitrogen atmosphere, and 100 ml of water are added to the residue and again evaporated. The resulting viscous yellow oil is suitable directly for the oxidative combination, but it is more convenient to convert it to the hydrochloride. To do this, it (1-methylpyridov-, 2-hydrazone) is treated with 120 ml of 37% hydrochloric acid, cooled to 0 ° C, the precipitate is filtered, crystallized from 50% alcohol and get 129 g of 1-methylpyridone hydrochloride hydrazone with a yield of 81%, and so on. pl. 255 - 256 ° С (with decomposition). Example 4. To 6.35 g of 2-aminobenzthiazole in 40 ml of dichloroethane, 4 ml of dimethyl sulfate are poured in at boiling, boiled for another 3 hours, 75 "l of water are poured, dichloroethane is poured with water, the solution of 3-methyl-2-aminobenzethiazolium methyl sulfate is filtered , for 2 hours, 6 ml of hydrazihydrate (мл ml of water) is poured into the boiling solution, boiled for 1 hour, cooled, the precipitate is filtered, washed and existed. 6.9 g of 3-methylbenzthiazolop -2-hydrazone are obtained with a yield of 91% (on 2 aminobenzthiazole), and so on. 138-, 140 ° С (from alcohol). Similarly, from 3-aminobenzthiazole and diethyl sulfate, Z-ethylbenzthiazolone-2 hydrazone with m.p. 76-77 ° C. Example 5. To 6 g of 2-amino-4-chlorobenzthiazole in 40 ml of dichloroethane, 4 ml of dimethyl sulfate are poured, heated to a boil, and boiled for 4 hours. Then it is diluted with 50 ml of water and the dichloroethane is distilled off with water. The solution of 3-methyl 4-chloro-2-aminobenzethiazolium methyl sulfate is cooled, filtered and slowly introduced into a boiling solution of 5.5 t for 3 hours.