| 摘要 |
<p>Disclosed is an improved process for the preparation of 4,5-diamino-1-(2'-hydroxyethyl)pyrazole and acid addition salts thereof such as the addition salt from sulfuric acid. The process comprises a novel combination of steps beginning with an alkyl (alkoxymethylene)cyanoacetate and 2-hydroxyethylhydrazine and the formation of intermediate compounds 5-amino-4-alkoxycarbonyl-1-(2'-hydroxyethyl)pyrazole (I), 5-amino-4-carboxyl-1-(2'-hydroxyethyl)pyrazole (II), 5-amino-1-(2'-hydroxyethyl)pyrazole (III), 5-amino-1-(2'-hydroxyethyl)4-nitrosopyrazole (IV),</p> |
