K. Yamagata, M. Takaki, Kimiko Ohkubo
Dec 13, 1993
Citations
0
Influential Citations
11
Citations
Journal
European Journal of Organic Chemistry
Abstract
The reaction of 4,5-dihydro-2-morpholino-(2-pyrrolidino and 2-piperidino)-3-thiophenecarbonitriles 1–3 with bis-(ethoxycarbonyl)carbenoid afforded stable dihydrothiophenium-1-bis(ethoxycarbonyl)methylides 4–6. The recyclization of compounds 4–6 with bases gave the corresponding diethyl 2,2(3H)-thiophenedicarboxylates 7 and ethyl 2-thiophenecarboxylates 7a′, 8, 9. The starting compounds 1–3 were synthesized by the reaction of 2-amino-4,5-dihydro-3-thiophenecarbonitriles with morpholine, pyrrolidine, and piperidine.