Process for the preparation of photochromic compounds of the annelated spiro[indoline[2,3'] benzoxazine]type

摘要

PCT No. PCT/FR94/00918 Sec. 371 Date Apr. 4, 1997 Sec. 102(e) Date Apr. 4, 1997 PCT Filed Jul. 22, 1994 PCT Pub. No. WO96/03368 PCT Pub. Date Feb. 8, 1996The present disclosure relates to a process for the preparation of photochromic compounds of the annelated spiro[indoline[2,3']benzoxazine] type comprising the reaction of a Fisher base (I) having a 2-alkylidene indoline structure with a condensed ortho-aminophenol compound (II) in the presence of an oxidizing agent. The Fisher base, condensed ortho-aminophenol and the oxidizing agent may be mixed together simultaneously in order to carry out the reaction. Alternatively, the oxidizing agent may be reacted with the Fisher base in a first step and condensed ortho-aminophenol may then be added to the reaction mixture thus obtained.