The Direct Knorr Synthesis of 2-Pyrrolecarboxamides
Paine, J.B. and David Dolphin
J. Heterocycl. Chem.
MeCOCH2CONEt2 and MeCOCH2CONMe2 were nitrosated with NaNO2 in AcOH and the resulting oximinoacetoacetamides treated with MeCOCH2COMe or MeCOCHMeCOMe under Knorr conditions to give pyrroles I [R = Ac, Me, R1 = Et; R = R1 = Me (II)]. II was oxidized with Pb(OAc)4 and the product treated with CH2 (CN) 2 in the presence of MeNH2 to give N,N-dimethyl-5-(2,2-dicyanovinyl)-3,4-dimethylpyrrole-2-carboxamide.