Sydnones IV. Synthesis of Sydnones Analogous to the Photochromic Compounds

Abstract N‐(6‐methoxy‐3‐pyridyl)‐sydnone (I), N‐(4‐nitrobenzyl)sydnone (II‐1), and N‐(2‐nitrobenzyl)sydnone (II‐2) have been prepared. Condensation of 2, 4‐dinitrochlorohenzene with N‐(carbethoxymethyl)sydnone (II‐4) produced N‐[(2, 4‐dinitrophenyl) carbethoxymethyl]‐sydnone (II‐5). Under normal conditions none of them are photochromic.