New reactions of pyrroles. II. Preparation and reactions of pyrroleglyoxyloyl derivatives

Abstract

Abstract Pyrroles treated with oxalyl chloride produced pyrroleglyoxyloyl chlorides. Unsubstituted and C‐alkyl pyrroles gave products stable only at low temperatures. N ‐Substitution or presence on the ring of an electron withdrawing group ( e.g . carbonyl) increased the stability of the glyoxyloyl chlorides considerably. Substitution occurred at the 2‐position unless both 2 and 5 positions of the pyrrole nucleus were blocked. When this was the case substitution occurred slowly at position 3.