| 摘要 |
1437208 2-Hydrazino-benzothiazoles ELI LILLY & CO 9 Oct 1973 [10 Oct 1972] 47061/73 Heading C2C A process for the preparation of 2-hydrazinobenzothiazoles haying the formula wherein R is hydrogen, halogen, (C 1 -C 3 ) alkyl, alkoxy or alkylthio and n is 0, 1 or 2, comprises reacting a corresponding 2-aminobenzothiazole of the formula wherein R<SP>1</SP> is hydrogen or methyl, with hydrazine in the presence of at least a catalytic amount of acid. The reaction is preferably conducted in an inert solvent selected from (C 2 -C 4 )-alkylenediols; di- and tri-(ethylene and propylene) glycols; mono-(C 1 -C 4 -alkyl) ethers of mono-, di- and tri-(ethylene and propylene) glycols. triethanolamine, sulpholane and dimethylsulphoxide. |
