| 摘要 |
The invention provides a process for preparing azetidine-3-carboxylic acid or salts thereof; useful as chemical hybridizing agents, which comprises treating a compound of the formula <IMAGE> (I) wherein R represents a hydrogen atom or a group of formula R1R2CH- wherein R1 and R2 are independently selected from hydrogen, alkyl or optionally substituted phenyl moieties, with nitric acid and subjecting the resulting initial product to acid conditions to produce an acid-addition salt of azetidine-3-carboxylic acid, and thereafter, if desired, converting the acid-addition salt to the free acid or another salt of the acid, 1-nitrosoazetidine-3,3-dicarboxylic acid, 1-nitrosoazetidine-3-carboxylic acid and salts thereof being intermediates in the process. |
