Lactams—I : The synthesis and acid hydrolysis of 4- and 5-substituted 1-benzyl-2-piperidone derivatives☆

摘要: Abstract In order to explain the difficulty in hydrolysing lactam linkage of 1-benzyl-2-oxo-5-ethyl-4-piperidineacetic acid (XIV) under conditions, several model compounds such as 1-benzyl-2-piperidone (X), 1-benzyl-5-ethyl-2-piperidone (XI), 1-benzyl-4-ethyl-2-piperidone (XII) and 1-benzyl-2-oxo-4-piperidineacetic add (XIII) were prepared their hydrolysis boiling 6N HCl was studied. For each lactams, found proceed an equilibrium shown Table 1. Substituents at 4- 5-positions piperidone ring seemed favour form between piperidones (X-XIV) ω-amino hydrochlorides (type XV).