4-Hydroxy pyrrolidin-2-onyl-amides

Claim 1

A process for the preparation of pyrrolidine compounds of the formula: ##STR4## wherein n is 1, 2 or 3, R 1 and R 2 , which can be the same or different, are hydrogen or alkyl having 1 to 3 carbon atoms and the asterisk indicates the center of asymmetry of the molecule, either as separated enantiomers or as a mixture thereof, comprising (1) reacting γ-amino-β-hydroxybutyric acid, either as separated enantiometers or as a mixture, under anhydrous conditions with a silylating agent, (2) reacting the product obtained, in the presence of an acid acceptor, with a halogen compound of an ester of an aliphatic acid of the formula Hal(CH 2 ) n --COOR, in which Hal is bromine, chlorine or iodine, R is alkyl having 1 to 4 carbon atoms, trichlorophenyl, nitrophenyl or trichloroethyl and n has the same meaning as above, (3) cyclizing to give a silyl compound of the formula: ##STR5## in which R' is methyl or ethyl and n, R and the asterisk have the same meanings as above, (4) hydrolyzing compound (II) to give the corresponding 4-hydroxy compound and (5) then reacting said 4-hydroxy compound with ammonia or with a mono- or disubstituted amine of the formula R 1 .NH.R 2 , in which R 1 and R 2 have the same meanings as above except that both cannot be hydrogen atoms.