Reactions of heterocumulenes with organometallic reagents: XII. Reaction of metallated vinyl ethers with isocyanates: Ingenious synthesis of pyruvic acid amides
摘要:
Acid hydrolysis of 2-alkoxy-N-substituted acrylamides easily obtained by reacting alpha-metallated vinyl ethers with isocyanates proceeded regiospecifically leading to the formation in a high yield of virtually undescribed and difficultly available 2-oxo-N-substituted propanamides.
Metalated alkoxy- and alkylthioethenes readily add to isocyanates, and subsequent hydrolysis or alkylation of the adducts gives N-mono- and N,N-disubstituted 2-alkoxy- and 2-(alkylthio)acrylamides in up to 86% yield. The reactions with propyl and phenyl isocyanates do not stop at the stage of addition of one isocyanate molecule, and further addition leads to formation of linear and cyclic polyamide structures.