Efficient Synthesis of 1-Aryl-4-[(ethoxycarbonyl)oxy]-1H-pyrazole-3-carboxylates

Abstract

Two‐step synthesis of N‐aryl 4‐[(ethoxycarbonyl) oxy]‐1H‐pyrazole‐3‐carboxylates is achieved starting from the commercially available ethyl 4‐chloroacetoacetate and aromatic amines. Azo coupling followed by cyclization with ethyl chloroformate–DMAP pair resulted in the formation of new 4‐oxy‐1H‐pyrazole derivatives in high yields.

The Structure ofN‐phenyl‐pyrazoles and Indazoles: Mononitro, Dinitro, and Trinitro Derivatives

“…37 : torsion = 29.9°; N1 = 112.1°, N2 = 104.6°, Δθ = 7.5°. 38 : torsion = 7.2°; N1 = 112.7°, N2 = 105.1°, Δθ = 7.6°.…”