Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The reaction of 2-hydroxyethyl methacrylate with 3-nitrophthalic anhydride catalyzed with triethylamine results in the 3 : 1 mixture of two possible monoesters, the more populated one being that with the ester group in ortho position to the nitro group. The isomers were identified and quantified by ¹H and ¹³C 1D and 2D techniques including APT, INEPT, superselective long-range (SSLR) INEPT, SSLR HHCR, COSY, NOESY, HETCOR and COLOC. Theoretical analysis was done on the model reaction of methanol with the anhydride using semiempirical AM1 quantum chemical calculations. The results indicate that the relative regioselectivity of the reaction is due to both the electron distribution in the anhydride molecule and hydrogen bonding in the stages immediately preceding the transition state.

Keywords: Regioselectivity of esterification; NMR; Quantum chemistry.