Synthesis and NMR study of 9′‐substituted spiroindolinonaphthoxazine derivatives

Abstract

A photochromic spiroindolinonaphthoxazine derivative, 1,3,3‐trimethyl‐9′‐hydroxy‐spiro[indoline‐2,3′(3H)‐ naphtho[2,1‐b][1,4]oxazine] 3 was synthesized by condensation of 1,2,3,3‐tetramethylindolenium iodide 1 and l‐nitroso‐2,7‐dihydroxynaphthalene 2. Further, two new derivatives, 5 and 7, were prepared in good yields by the reactions of 3 with the hexafluoropropene trimer 4 and 4‐[perfluoro(2‐isopropyl‐1,3‐dimethyl‐1‐butenyl)‐oxybenzoyl chloride 6, respectively. Their unique structural features and property are discussed based on ¹H‐, ¹³C‐ and ¹⁹F nmr spectral data.