Synthesis of some long-chain spiropyranindolines

Abstract

Nine new spiropyranindolines containing an n-hexadecyl substituent at the 1′ or 3′ position have been synthesized. Their spectral properties (nmr, uv, visible) are described.The equilibrium constant between the colored and colorless species of some of the compounds have been measured. The results show that the presence of a long aliphatic chain promotes the colored form.