The position of the thermodynamic equilibrium for reverse thermochromic spiropyran 6-carboxylates (SPCOOHs) was easily determined in aqueous binary mixtures, such as water-methanol, water-acetonitrile and water-dimethyl sulfoxide. The existence of more than one type of interconvertible species of the ring-opened form of SP-COOH in aqueous binary solvents enables us to evaluate the molar extinction coefficients of the ring-opened species of SP-COOH and to obtain the thermodynamic parameters.

An efficient one‐pot preparation of aryl‐(E)‐2‐(azidomethyl)alkenoate and aryl‐(Z)‐2‐(azidomethyl)acrylonitrile from aryl aldehydes and activated alkenes (acrylate and acrylonitrile) were developed. The method consisted of a three‐step one‐pot process involving Baylis–Hillman reaction of aryl aldehydes and activated alkenes using DABCO followed by acetylation using acetic anhydride and a catalytic amount of DMAP, and nucleophilic substitution with sodium azide in DMF at room temperature.

The title compounds are prepared by a three‐step one‐pot process involving a Baylis—Hillman reaction of aryl aldehydes and activated alkenes followed by acetylation using acetic anhydride and nucleophilic substitution using sodium azide.