DE812551C - Process for the preparation of pyrrolidone derivatives - Google Patents

Description

Process for the preparation of pyrrolidone derivatives It has been found that valuable pyrrolidone derivatives are obtained if r-lactones, which are substituted by oxy or amino groups or their alkyl, Arvl or Acvl derivatives, at higher temperatures with ammonia or primary Converts amines. The implementation takes place z. B. according to the scheme where X denotes an OH or NH2 radical or their derivatives and R denotes an H atom, an alkyl, cycloalkyl or aryl radical.

Suitable starting materials are, for. B. the a-oxybutyrolactone, the a, ß-dioxybutyrolactone, also the a-methoxy or a-phenoxybutyrolactone, the a-amino, -phenylamino or -dimethylaminobutyrolactone, the a-benzoylaminobutyrolactone or the a-phthalimidobutyrolactone and their C -Alkyl or aryl derivatives. The primary amines that can be reacted with these lactones to form pyrrolidones are, for. B. methyl and ethylamine, ethanolamine, cyclohexylamine, dodecylamine and aniline are mentioned. The IMPLEMENTATION carried out at temperatures above about ioo 'sufficiently rapidly; it is best to work at temperatures between about 10 and 25 °, in which case the ammonia or amine is expediently used in excess and, if desired, solvents such as methanol and dehydrating agents such as aluminum oxide are also used.

The Pyrrohdon derivatives thus obtainable in a simple manner with very good yields are valuable intermediate products, especially for plastics, dyes and pharmaceuticals Middle.

The parts mentioned in the examples are parts by weight.

Example i 50 parts of α-oxybutyrolactone are heated to 230 ° for 5 hours with 40 parts of liquid ammonia in a pressure vessel. The pressure rises to 43 atm. After cooling, the reaction product is distilled, the α-oxypyrrolidone passing over at 10 mm pressure and ig, 4 '. It solidifies on cooling and melts at 75 '. Example 2 95 parts of aN-methyl-N-phenylaminobutyrolactone are heated to 23 ° in a pressure vessel for 5 hours with 40 parts of liquid ammonia and 2oo parts of methanol. Then the methanol and the excess ammonia are distilled off. The αN-methyl-N-phenylaminopyrrolidone distills over from the residue under 10 mm pressure at 239 to 241 '.

EXAMPLE 3 178 parts of a-phenoxybutyrolactone are heated to 25 ° with 99 parts of cyclohexylamine in an autoclave for 5 hours. The reaction product, which is in the form of a crystalline mass, is recrystallized from methanol. The α-phenoxy-N-cyclohexylpyrrolidone with a melting point of up to 120 ° is thus obtained in very good yield in the form of colorless, matted needles. EXAMPLE 4 2o5 parts of α- (N-ethyl-N-phenyl) -aniinobutyrolactone and: 20 parts of active aluminum oxide, such as can be obtained by precipitating aluminum salt solutions with ammonia and dehydrating the precipitated hydroxide, are placed in an autoclave. 35 parts of anhydrous ammonia are added to this. The mixture is heated to 23 ° for 5 hours, then the excess ammonia is removed, the residue is dissolved in methanol and the aluminum oxide is filtered off. After the 1 # ethanol has been distilled off, the α- (N-ethyl-N-phenyl) aminopyrrolidone passes over in good yield under 2 mm pressure at 24o to 245 '.

Claims (1)

PATENT CLAIM: Process for the preparation of pyrrolidone derivatives, characterized in that 7-lactones which are substituted by oxy or amino groups or their alkyl, aryl or acyl derivatives, at higher temperatures with ammonia or primary amines, optionally under pressure and in the presence of inert solvents and water-releasing agents.