| 摘要 |
A process for making 5-mercapto-1,2,3-triazoles of the formula <IMAGE> I wherein R1 is hydrogen or a C1-C4-alkyl which may also be substituted, the said process comprising (1) as a first step reacting a solution of 1,2,3-thiadiazole-5-carbohydroxamic acid derivative of the formula <IMAGE> II wherein R1 has the meaning as above and R2 is hydrogen or a univalent metal equivalent in an inert organic solvent in the presence of an acid acceptor with a solution in an inert organic solvent of an acid halide of the formula R3-X so as to form an acylated 1,2,3-thiadiazole-5-carbohydroxamic acid derivative (2) reacting as a solution in an inert organic solvent the carbohydroxamic acid derivative just obtained with an alcohol or phenol of the formula H-O-R4 so as to form a (1,2,3-thiadiazole-5-yl)-carbamic acid ester (3) then treating the thus obtained carbamic acid ester with an acetic or basic catalyst to form the 5-amino-1,2,3-thiadiazole (4) whereupon the said amino thiadiazole is subject to a rearrangement in the presence of a base followed by isolation of the product of the reaction. |
