Homogeneous Gas Phase Pyrolysis of 7V-t-Butylacetamide

Abstract

The kinetics of the gas phase pyrolysis of N-t-butylacetamide have been studied in a static system over the temperature range 385–465°C. The decomposition occurs by two simultaneous, homogeneous and unimolecular processes. The major process (1) is the elimination of isobutene and the formation of acetamide; the minor process (2) is the elimination of t-butylamine and the formation of ketene. CH3CONHC(CH3)3[graphic omitted](CH3)2C[double bond, length as m-dash]CH2C + CH3CONH2(1), CH3CONHC(CH3)3[graphic omitted](CH3)3CNH2+ CH2[double bond, length as m-dash]C[double bond, length as m-dash]O. (2) The rate constant for reaction (1) in the Arrhenius form is k1= 1012.42 exp (– 51 540/RT) s–1(R in cal mol–1 K–1). The acetic acid formed by subsequent decomposition of the acetamide catalyses the formation of t-butylamine and the rate constant for this bimolecular process between 400–452°C is given by k3= 1013.56 exp (– 34 950/RT) cm3 mol–1 s–1. The transition state for reaction (1) is believed to be six-centred.