Process for the preparation of lactam derivatives.

摘要

The invention relates to a process for the preparation of a compound of formula (I) <CHEM> wherein R represents a hydrogen atom or a methyl or ethyl group, which comprises cyclising a compound of formula (IV) <CHEM> Where R represents a hydrogen atom, the compound of formula (IV) may optionally be alkylated to produce a compound in which R is methyl or ethyl. The compound of formula (I) is useful as an intermediate in the preparation of 2,3,4,5-tetrahydro-2-[(imidazol-4(or5)-yl)methyl]-1H-pyrido[4,3-b]indo l-1-ones having 5-HT3 antagonist activity.