首页>
外国专利>
IMPROVEMENT IN OR RELATING TO THE MANUFACTURE OF OXYPHENEBUTAZONE(1-(-P-HYDROXYPHENYL)-2-PHENYL-4-BUTYL-3,5-DIOXOPYRAZOLIDINE)FROM P-BENZYL-OXYAZOBENZENE AND N-BUTYL MALONIC ESTER
IMPROVEMENT IN OR RELATING TO THE MANUFACTURE OF OXYPHENEBUTAZONE(1-(-P-HYDROXYPHENYL)-2-PHENYL-4-BUTYL-3,5-DIOXOPYRAZOLIDINE)FROM P-BENZYL-OXYAZOBENZENE AND N-BUTYL MALONIC ESTER
An improved process for the preparation of oxyphenbutazone [1-(p-hydroxyphenyl)-2-phenyl-4-butyl-3, 5-dioxopy-razolidine] which comprises reducing p-benzyloxyazobenzene with zinc dust in alcoholic sodium hydroxide and nitrogen atmosphere to form p-benzyloxy hydroazobenzene followed by reacting the said p-benzyloxyhydrazobenzene with n-butyl malonic ester in presence of sodium ethoxide solution of temperature not exceeding 145 Degree Celsius with stirring and distillation of ethanol to form 1-(p-benzyloxyphenyl)-2-phenyl-4-butyl-3-5-dioxypyrazolidine as an intermediate product which is do benzylated by methods known per se to oxyphenbutazone.
展开▼
