Hitherto unknown 6-hetaryl-4,5,7,8-tetrahydropyrrolo[1,2-a]thieno[3,2-e]pyrimidine-4,7-diones (7a-7g) were prepared by reaction of ethyl 2-aminothiophene-3-carboxylates 5 with 4-chloro-2-hetaryl-3-oxobutanonitriles 4 in DMF at 100 °C. When the same reagents were treated in the presence of triethylamine, a dependence of the reaction pathway on the nature of the hetaryl substituent in chloronitrile component was observed. This was explained in terms of steric factors.
迄今为止未知的6-杂环基-4,5,7,8-四氢吡咯并[1,2-a]噻吩[3,2-e]嘧啶-4,7-二酮(7a-7g)通过在100°C下将乙基2-氨基噻吩-3-羧酸乙酯5与4-氯-2-杂环基-3-氧代丁酰氰4在DMF中反应制备。当相同的试剂在三乙胺存在下处理时,观察到反应途径依赖于氯代腈组分中杂环基取代基的性质。这可以用空间位阻因素来解释。