A process for preparing a compound of formula (I)
wherein X is phenyl optionally substituted by one halogen, C1-4 alkyl or Cl-4 alkoxy; or pyridyl; R1 is hydrogen or C1-6 alkyl; and n is an integer of from 1 to 6; which process comprises, cyclising a compound of formula (II)
wherein X, R1 and n are as defined in relation to formula (I); Y is an hydroxy or an acid activating group and Rx is hydrogen or an N- protecting group and thereafter if desired carrying out one or more of the following steps: (i) removing any protecting group Rx, (ii) preparing a salt of the compound of formula (I).
一种制备式(I)化合物的工艺
其中 X 是任选被一个卤素、C1-4 烷基或 Cl-4 烷氧基取代的苯基;或
吡啶基;R1 是氢或 C1-6 烷基;n 是 1 至 6 的整数;该工艺包括:将式(II)化合物环化
其中 X、R1 和 n 如式(I)所定义;Y 是羟基或酸活化基团,Rx 是氢或 N-保护基团,然后根据需要进行以下一个或多个步骤:(i) 去除任何保护基团 Rx,(ii) 制备式 (I) 化合物的盐。