純硫酸中シクロヘキサンカルボン酸フェニルエステルのニトロシル硫酸によるニトロソ化反応の速度論

抄録

The rates of the nitrosation of phenyl cyclohexanecarboxylate (abbreviated as PCC) with nitrosyl hydrogensulfate (NHS) in 0-7% oleum to form ε-caprolactam have been investigated by measuring the volume of evolved carbon dioxide. The rate equation of the reaction is written as follows : Rate=(κ_1e+κ_2esC_so3+κ_2enC_NHS)C_PCC A probable mechanism which involves the rate-determining steps of formation of pentamethylene ketene (PMK) by deprotonation from cyclohexanecarbonyl cation formed by elimination of phenolate anion and sulfur trioxide from an adduct of PCC and SO₃ (κ₁, main path, 90.4%), and by the elimination of SO₃, phenol and proton from the adduct (κ_2es, 5.3%) followed by a rapid attack of NHS on the double bond of PMK, and a rate-determining formation of cyclohexanone oxime hydrogensulfate from the adduct of NHS and PCC (κ_2en, 4.3%) was discussed and postulated.