ACYLATION OF 1-(BETA-HYDROXYETHYL)-3,3-DIMETHYL-6′-NITROSPIROINDOLINE-2,2′-(2H-1)-BENZOPYRAN

1. 1-(β-Hydroxyethyl)-3,3-dimethyl-6′-nitrospiro(indoline-2,2′[2H-1]benzopyran) (I) exists in solution as two isomeric forms. The value of the equilibrium constant varies as a function of the solvent polarity and is (513 ± 154) · 10−4 for the ethanol solution. 2. The mechanism proposed for the acylation of compound (I) includes the reaction of the acid chloride with both isomeric forms. 3. Based on the obtained data, the method for the synthesis of 1-(β-methacryloyloxyethyl)-3,3-dimethyl-6′-nitrospiro(indoline-2,2′[2H-1]benzopyran) was improved, which made it possible to increase the yield of the product up to 60%.