| 摘要 |
<p>The present invention relates to a process for the preparation of compounds of formula (b), in which a compound of formula V is reacted with a compound of formula VI. The resulting compound of formula IV is reduced to a compound of formula III which is hydrolysed to a compound of formula (b). Alternatively, a compound of formula IV is hydrolysed to a compound of formula (a) which reduced to a compound of formula (b). Compounds of formula IV are novel. In the formulae the variables are as defined in the claims. <CHEM></p> |
