One-pot synthesis of lactams from cycloalkanes and tert-butyl nitrite by using N-hydroxyphthalimide as key catalyst.

Lactams were successfully synthesized in the one-pot reaction of cycloalkanes and tBuONO in the presence of N-hydroxyphthalimide as a key catalyst. Cyclododecane and cyclohexane were treated with tBuONO followed by triethylamine and then cyanuric chloride in a one-pot manner to give laurolactam and epsilon-caprolactam, respectively, in good yields. The Beckmann rearrangement of oximes by cyanuric chloride was found to be accelerated by the use of 1,1,1,3,3,3-hexafluoro-2-propanol as solvent. The method provides the first successful environmentally benign direct synthetic route to lactams from cycloalkanes without the formation of any salt.