摘要 |
The present invention relates to a method for the preparation of an imidazolyl compound of the general formula (I), wherein: Ra and Rb each separately are (C1-C6)alkyl, (C1-C6)alkoxyalkyl, optionally substituted aryl or heteroaryl; or wherein Ra and Rb together form a further homocyclic or heterocyclic system comprising one or more rings; Ra' and Rb' each are hydrogen or together form a carbon-carbon double bond, said carbon-carbon double bond optionally being part of an aromatic system; Rc is hydrogen, (C1-C6)alkyl, (C1-C6)alkoxy, (C1,-C6)alkoxyalkyl or halogen; Rd is hydrogen or (C1-C4)aIkyl; Re is hydrogen or (C1-C4)aIkyl; m is 1 or 2; and R1, is hydrogen or (C1-C4)aIkyl; as well as its acid addition salt;characterized in that a compound of the general formula (II) is reacted with a compound of the formula (III), wherein: R is a hydrogen, a (C1-C4)alkyl group optionally substituted with a hydroxygroup or an optionally substituted aryl group, R', R", R'" and R"" each individually are a hydrogen or a (C1-C4)aIkyl group; followed by a reaction with a compound of the formula (IV), wherein R1, Rd and Re have the meanings defined above; and optionally followed by a reaction with a suitable acid. De method according to the present invention is especially useful for the preparation of ondansetron and cilansetron. |