| 摘要 |
The novel process for preparing the title compounds of the formula <IMAGE> where R, R<1>, R<2> and R<3> are independently H or C1-3 alkyl comprises reacting a compound II with a compound III <IMAGE> Compounds III, which are claimed per se, can be prepared by reaction of corresponding 1-methylthio-1-alkylamino-2-nitroethenes with ethyleneimine in the presence of thiophilic metal ions. Compounds II, which are claimed per se, may be prepared by introduction of the mercapto group. Processes for the preparation of compounds V: <IMAGE> where X is Cl, Br or -S-C(NH)NH2 are also claimed. |
