Abstract: The homogenous gas phase pyrolysis of ethyl acetamide is studied by MINDO/3 molecular orbital method.The results show that the major process proceeds via a six membered ring transition state (TS), but the four membered ring TS is also feasible, which is not accessible in the gas phase pyrolysis of esters. A detail analysis of Intrinsic Reaction Coordinate(IRC) is used to elucidate the reaction mechanism. The results also reveal that the change of activation energy in the polar solvent is not evident, in other words, the catalysis by carboxylic acid is not marked for the gas phase pyrolysis of ethyl acetamide.

Key words: Gas phase pyrolysis, Molecular orbital method, Ethyl acetamide