SU378087A1 - Method for preparing substituted 4 = (2 = hydroxyaryl) = semicarbazides - Google Patents

Description

(54) METHOD FOR OBTAINING SUBSTITUTED 4- (2-OXYARIL) - SEMICARBAZIDES The invention relates to a crawling method for semicarbazides, in particular new substituted 4- (2 -oxyaryl) -semicarbazides, which have biologically active properties. Two compounds are known from the series of 4- (2-hydroxyaryl) -semicarbazides, namely, 4- (2-hydroxyphenyl) -semicarbazide and 4- (2-hydroxy-4-nitrophenyl) -semicarbazide, which are obtained by reacting benzoxazo-inone-2 and 6-nitrobenzoxazolinone-2 with an excess of hydrazine hydrate in eight times the volume of ethanol. However, the known 4- (2-hydroxyaryl) -semicarbazides have an insufficiently wide spectrum of fungicidal action. Therefore, the synthesis of various substituted 4- (2-oxoaryl) -semicarbazides and the study of their biologic activity currently does not lose its actual ™. In order to obtain new compounds possessing better compared with the known properties, they offer a method for removing compounds of general formula II -C-Na with OH where X is hydrogen, halo, nitro, amino, ulfaminogroup, R is hydrogen, alkyl, phenyl; R R, R, is hydrogen or alkyl; p, 1 - 3. The method is based on the well-known method of benzoxazoline ring cleavage by the action of hydrazines or hydrazine hydrates. The proposed method consists in that benzoxazolinone-2 of general formula 4 K, where R has the above meaning, is reacted with hydrazine or hydrazine dihydrate of general formula R NHNRR, where R, R R have the indicated warmth. The process is carried out mainly at a temperature of 90-120 ° C without solvent.

PRI me R 1. 4.28 g of 6-bromobenzoxazolinone-2 and 1,1-gadrasine hydrate are thoroughly mixed and heated to reflux at 110-120 ° C for 2-3 minutes. The volatile products are removed in vacuo and 4-- (2 -oxy-4-bromophenyl) - semicarbazide (1) is obtained, yield 4.8 g, m.p. 182-183 ° C (from alcohol).

PRI mme R 2. From 17.1 g of 6-chlorobenzoxazolinone-2 and 5.5 ml of gadrazingadrate as in Example 1, 4- (2-hydroxy-4-chlorophenyl) -semicarbazide (2) is obtained, yield 19.2 g m.p. 181-182 ° C, (from dioxane).

Example From 1.7 g of 5-chlorobenzoxazolinone-2, 0.55 ml of hydrazine hydrate and 1 ml of water under similar conditions, 4- (2-oxy-5-chlorophenyl) -smicrocarbazide (3) are obtained, yield 1.7 g, m.p. 172-173 ° C (from alcohol).

EXAMPLE 4: 9.6 g of 4,5,6-trichlorobenzoxazolinone-2 and 2 ml of gadrasine hydrate are thoroughly mixed, heated for 10 minutes with a reverse of 1 m refrigerator at a bath temperature of 115-120 ° C, 8 ml of water are added and another 10 min, then recrystallize from dioxane, get 4- (2-oxy-4, 5, b-trichlorophenyl) -semicarbazide (4), yield 8.96 g

Example5. From 1 g of 6-sulfaminobenzoxazolinone and 0.45 ml of hydrazine hydrate as in Example 1, 4- (2-hydroxy-4-sulfamino-phenyl) -semicarbazide (5) is obtained, which melts at a temperature of 181-183 ° C, yield 1.18 g. After recrystallization from Waters receive 0.85 g (68.5%) of the product with T.PL. 195-196 ° C (with decomposition).

EXAMPLE 6 A mixture of 2.8 g of N-methyl benzoxazolinone-2 and 1.1 ml of hydrazine hydrate is mixed thoroughly, 1 ml of water is added and the mixture is heated

conditions are frozen; 1, the peptides, the products are removed in vacuo, treated with benzene (or ether) to obtain 4-me1IL-4- (2-hydroxyphenyl) semicarbazide (6), yield 1.54 g (45.6%).

EXAMPLE 7 5.4 g of bepsoxazolinone-2 and 2.8 m of N, N-dimethylhydrazine are heated in a sealed ampoule at a bath temperature of 115-120 ° C for 1 hour with occasional shaking, after which the molten zakristallizoz mass of 11 bast. The reaction mass is held for another 20–30 min under the same conditions, then cooled, the ampoule is opened, treated with sfir, filtered, and dried. 4.25 g (54.5%) of 1,1-dimethyl-4- (2-hydroxyphenyl) semicarbazide are obtained, m.p. 177.5-178 ° C (7).

PRI me R 8. A mixture of 5.1 g of benzoxazolinone. and 3.5 ml of N, N-dimethylhydrazine is heated at a bath temperature of 90-100 ° C for 20 ms. The reaction mass is cooled, treated with ether, filtered, crystallized from alcohol to obtain 1,2-dimethyl-4- (2-hydroxy-4-chlorophenyl) -semicarbazide, yield 5.3 g (77%) (8).

Under the same conditions, compounds 9–11, 14–16, but upon preparation 9 and 10, are heated for 5 minutes at a bath temperature of 115–120 ° C of R and me R 9. A mixture of 7.2 g of finely ground 4,5,6- trichlorobenzoxazolinone and 5.8 ml of phenyltadrazine are heated for 10 minutes at a tempere tour bath of 120 ° C and after treatment with ether and GSrecularization from dioxane, 8 g (77%) of pro; 1; uct are obtained. The table shows the radicals of the various examples given in the examples, 4- (2-hydroxyaryl) - semicar basides, physical properties, and data on their analysis;

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Claims (2)

Claims 1. Method for preparing substituted 4- (2-hydroxy) -semicarbazides of general formula I ABOUT one / R NR-C-N-N R2 R. HE where X is hydrogen, halide, nitro-sulfamide;  hydrogen, alkyl, phenyl; R, R R is hydrogen or alkyl; n 1-3, different the fact that benzoxazolinone-2 of General formula 11 NR Hgg 0 where R has the above meaning, is subjected to interaction with hydrazine or gadrasingidrat General formula III R NHNRR where R, R and R have the above meaning, followed by the separation of the target product by known techniques. 2. A method according to claim 1, characterized in that the progressing is carried out at 90-120 ° C.