186581-53-3
重氮甲烷
+
624-48-6
马来酸二甲酯
→
126416-42-0
dimethyl 4,5-dihydro-3H-pyrazole-3,4-dicarboxylate
87387-81-3
dimethyl 4,5-dihydro-1H-pyrazole-3,4-dicarboxylate