| 摘要 |
Lactams are prepared by treating an o -hydroxy-fatty acid nitrile containing four to eight, especially four to six, carbon atoms and having a chain of at least three carbon atoms between the -OH and -CN groups with a molar excess of ammonia or a primary amine at a temperature of 200-350 DEG C. and at increased pressure, usually 50-150 atmospheres or above. The reaction may be carried out in the presence or absence of water and may be performed continuously or discontinuously, the products generally being obtained from the reaction mixture by distillation. The use of amines produces N-substituted lactams and diamines may be used to prepare bis-lactams. Preferred amines are alkyl amines containing 1-12 carbon atoms, cycloalkyl amines containing 5-12 annular carbon atoms, aniline and its homologues, aralkyl amines containing a mononuclear aromatic ring and an alkyl radical containing 1-4 carbon atoms, and diamines containing 2-12 carbon atoms. Namerous amines are specified. The o -hydroxy-fatty acid nitriles may be obtained by reaction of o -halogen alcohols with alkali cyanides or as by-products in the reaction of a ,o -dihaloalkanes with alkali cyanides in aqueous alkaline solution. In examples: (1) d -hydroxyvaleronitrile, concentrated aqueous ammonia and water give a -piperidone: (2) #c-hydroxybutyronitrile and concentrated aqueous ammonia give a -pyrrolidone: (3) e -hydroxycapronitrile and concentrated aqueous ammonia give caprolactam: (4) d -hydroxyvaleronitrile and aqueous methylamine give N-methyl-a -piperidone, excess aqueous methylamine being utilizable in a further batch: (5) d -hydroxyvaleronitrile and aqueous ethylamine give N-ethyl-a -piperidone: (6) d -hydroxyvaleronitrile, n-butylamine and water give N-(nbutyl)-a -piperidone: (7) d -hydroxyvaleronitrile, aniline and water give N-phenyl-a -piperidone; the use of p-toluidine instead of aniline yields N-(p-tolyl)-a -piperidone: (8) d -hydroxyvaleronitrile, 1,6-hexamethylene diamine and water give 1,6-hexamethylene - N,N1 - bis - (a - piperidone); 1,2-ethylene-N,N1-bis-(a -piperidone) is obtained similarly by the use of ethylene diamine in place of the hexamethylene diamine: (9) d -hydroxyvaleronitrile, benzylamine and water give N-benzyl-a -piperidone; N-cyclohexyl-a -piperidone is similarly obtained by using cyclohexylamine in place of benzylamine: (10) d -hydroxyvaleronitrile and liquid ammonia give a -piperidone: (11) g -hydroxybutyronitrile, aniline and water give N-phenyla -pyrrolidone. |
