Ethyl Vinyl Ether - An Agent for Protection of the Pyrazole NH-Fragment. A Convenient Method for the Preparation of N-Unsubstituted 4-Alkynylpyrazoles

Abstract

N-Unsubstituted 4-iodopyrazole (1) is easily converted into 4-alkynyl derivatives (5) in moderate to good overall yields by using intermediate protection of the nitrogen atom of the pyrazole ring by ethyl vinyl ether.