摘要 |
PROCESS FOR THE PREPARATION OF LACTAM DERIVATIVES The invention provides a process for the preparation of a compound of general formula (I): wherein Im represents an imidazolyl group of the formula: and R1 represents a hydrogen atom or a group selected from C1-6alkyl, C3-6alkenyl, C3-10alkynyl, C3-7cyaloalkyl, C3-7cycloalkylC1-4alkyl, phenyl, phenylC1-3alkyl, phenylmethoxymethyl, phenoxyethyl, phenoxymethyl, -CO2R5, -COR5, -CONR5R6 or -SO2R5 (wherein R5 and R6, which may be the same or different, each represents a hydrogen atom, a C1-6alkyl or C3-7cycloalkyl group, or a phenyl or phenylC1-4alkyl group, in which the phenyl group is optionally substituted by one or more C1-4alkyl, C1-4alkoxy or hydroxy groups or halogen atoms, with the proviso that R5 does not represent a hydrogen atom when R1 represents a group -CO2R5 or -SO2R5); one of the groups represented by R2, R3 and R4 is a hydrogen atom or a C1-6alkyl, C3-7cycloalkyl, C3-6alkenyl, phenyl or phenylC1-3alkyl group, and each of the other two groups, which may be the same or different, represents a hydrogen atom or a C1-6alkyl group; and n represents 2 or 3; which comprises reacting a compound of formula (II) or a protected derivative thereof, with a compound of formula (III): HOCH2-Im(III) or a salt thereof in the presence of an acid at an elevated temperature, followed where necessary by removal of any protecting groups. |