Synthesis of a variety of novel Z/E N‐(1‐chlorovinyl)formamides through Vilsmeier–Haack reaction starting from 2‐phenoxyethanamides with POCl3/DMF has been accomplished. The reactions introduced chlorine atom to the Cα‐position and phenoxy substitutions to the Cβ‐position of N‐vinylformamides, and the Z/E isomers of N‐(1‐chlorovinyl)formamide were isolated and characterized. In most cases, Z/E N‐(