Synthesis of benzyl and <i>tert</i>‐butyl 3‐(2‐methoxycarbonylethyl)‐4‐methylpyrrole‐2‐carboxylates from methyl 4‐oxobutanoate

Abstract

Abstract Condensation of methyl 4‐oxobutanoate with nitroethane in the presence of 4‐dimethylaminopyridine, followed by treatment with acetic anhydride, afforded a nitroacetoxyester 10b . Subsequent reaction with isocyanoacetate esters and DBU in refluxing tetrahydrofuran gave the synthetically valuable pyrroles 1a and 1b.