CS242009B1 - 6-substituted 2-benzothiazolehydrazine bromides - Google Patents

Description

The present invention provides 6-substituted-2-benzothiazolylhydrazinium bromides. Known is [Martino Colonna; publ. Inst. chim. Univ. preparation of 6-substituted hydrazines. Bologna 2.3 (1943); Boggust, W. Cocker; J. Chem. Soc. (1949) 362).

We have now found that compounds of the general formula

-h

The 10 ' 8r (n wherein X is hydrogen, the CH3, Cl, Br, NO2 group exhibits a stimulating and inhibitory effect.

At the same time, a process for the preparation of said hydrazinium salts was found. The reactions are carried out in a medium of HCl and stannous chloride at 0 ° C by reacting nitric acid with the corresponding 2-aminobenzothiazoles to produce the bromide by treatment with HBr.

The effect of the substance according to the invention can be used in mixtures with other known active substances.

The following examples illustrate but do not limit the preparation and properties of the compounds of the invention.

Example 1 - · ”......... ·; ^τ 2-benzothiazolylhydrazine

Dissolve 0.1 mole of 2-mercaptobenzothiazole in 50 ml of ethanol in a three-necked flask equipped with a stirrer. Then enough hydrazine hydrate (1 'of any concentration) is added to dissolve the benzothiazole cold. The mixture was refluxed for 8 hours. Upon cooling the reaction mixture, white needles are formed which, after washing with ethanol, have a melting point of 201-202 ° C. Yield 85%.

Empirical formula C7H7N3S M _r 165.21

analysis:

calculated:

% C: 50.60% H: 4.24% N: 25.43 0/0 S: 19.31 found:

% C: 50.63% H: 4.22% N: 25.18% S: 19.35

Example 2

2-Benzothiazolylhydrazinium bromide

0.05 g of 2-benzothiazolylhydrazine is suspended in 100 ml of ethanol, to which 0.1 mol of concentrated hydrobromic acid is added dropwise. The solid goes into solution. After standing at room temperature for 2 hours, white crystals of m.p. t. 274-5 ° C, yield 90%.

Molecular formula: C7H8N2SBr M _r 244.09

analysis:

calculated:

% C: 34.44% H: 2.47% N: 17.21% S: 13.13% Br: 32.82 found:

% C: 34.32% H: 2.29% N: 17.09% S: 12.98% Br: 32.67

Example 3

6-Methyl-2-benzothiazolylhydrazinium bromide

0.05 mole of 2-amino-6-methylbenzothiazole is dissolved in 150 ml of conc. hydrochloric acid. To this is added 0.05 mol of sodium nitrite dissolved in 9 ml of water. The temperature is maintained at 0 ° C. After two hours of reaction to the solution, 0.1 mol of stannous chloride and 20 ml of hydrochloric acid are added. The temperature is maintained at -5 to 0 ° C. The reaction mixture is stirred for an hour, then the precipitate is filtered off, washed with alcohol and ether and boiled in hot water and filtered carefully. Hydrogen sulfide was introduced into the filtrate. The precipitated tin (II) chloride is filtered off and the filtrate is concentrated. The 6-methyl-2-benzothiazolylhydrazinium chloride thus obtained is crystallized from ethanol, then the pure product is dissolved in 30 ml of cold water, poured in 0.08 mol of concentrated hydrobromic acid. After a reaction time of 24 hours at room temperature, 6-methyl-2-benzothiazolylhydrazinium bromide with m.p. t. 265 DEG-267 DEG. 95% yield.

Summary formula: CsH10N3SBr M _r 260.13

analysis:

calculated:

% C: 36.95% H: 3.87% N: 16.15% Br: 30.72 found:

C: 36.75% H: 3.59% N: 15.98% Br: 30.52 β

Example 4

6-Bromo-2-benzothiazolylhydrazmium bromide

The preparation procedure is the same as the example

3. The reaction product is white in color, with m.p. t. Mp 273-274 ° C.

Summary formula: C 7 H 7 N 3 SSB 2 M _r 325.01

analysis:

calculated:

% C; H: 25.86% N: 12.92% S: 9.86% Br: 49.17 found:

% C: 25.66% H: 2.32% N: 12.78% S: 9.53% Br: 49.00

Example 6

6-Chloro-2-benzothiazolylhydrazinium bromide

Preparation procedure as in Example 3. The isolated product is of white color with m.p. t. 281-282 ° C.

Molecular formula: C7H7N3SBrCl M _r 280.55

Example compound

2

Control equals 100%

Caste tests were performed by measuring the length of the primary roots in the elongation growth on the Vicia sativa L. plant object in a petri dishes, in a thermostate, in the dark at 25 ° C. The length of the primary roots was measured after 24 hours of incubation of the germs in molar solutions of the test substances. Climax. stim./24 h. molarity 10 ' ⁵ %

analysis:

calculated:

% C: 30.02% H: 2.60% N: 15.00% Br: 27.86 found:

% C: 29.83% H: 2.27% N: 14.89% Br: 27.52

Example 7

6-Nitro-2-benzothiazolylhydrazinium bromide

The preparation procedure is the same as in Example 3. The isolated crystals are yellow in color, m.p. t. 302 DEG-304 DEG. '

Summary formula: C7H7N4SB1O2 M _r 291.18

analysis:

calculated:

% C: 28.89% H: 2.43% N: 19.25% Br: 27.14 found:

% C: 28.81% H: 2.39% N: 19.07% Br: 26.98

Effect of synthesized compounds of the invention on the primary root extension of Vicia sativa L.

Maxim, inhibition / 24 h. molarity 10 ' ³ % - —12.38 - —87.88 - —93.28 - —49.70 +33.50 - hens after 48 hours growth were exposed on a 10' ¹³ to 10 ' ³ M concentration scale The experimental and control group consisted of 20 germinates in one Petri dish. The variant of the experiment contained 5 Petri dishes, representing 100 individuals in one variant. The experiment was repeated three times.

Claims (2)

SUMMARY OF THE INVENTION 1. 6-Substituted-2-benzothiazolylhydrazinium bromides of the formula I as defined above, characterized in that 6-X-2-aminobenzothiazole of formula II is reacted. wherein X is hydrogen, methyl, chloro, bromo or nitro. 2. A process for the preparation of 6-substituted-2-benzothiazolylhydrazinium bromides of Formula I wherein X is higher with nitrous acid and stannous chloride at 0 DEG C. in hydrochloric acid] and the product is prepared by hydrobromic acid bromide treatment. Severografla, n. P., Závod 7, Most Price 2,40 Kčs