WO2007110649A3 - Process for the preparation of 2,6,9-trisubstituted purines - Google Patents

Abstract

The present invention relates to a process for preparing a compound of formula (I), or a pharmaceutically acceptable salt thereof, wherein R2 is (a) where R3, R4, R7 and R8 are each independently selected from H, alkyl, aryl and aralkyl, said alkyl, aryl and aralkyl groups each being optionally substituted with one or more R12 groups, and wherein at least one of R3, R4, R7 and R8 is other than H; R5 is OH, O-alkyl, NH2, H, alkyl, aryl or aralkyl, said alkyl, aryl and aralkyl groups each being optionally substituted with one or more R12 groups; R6 is NR10R11, wherein R10 and R11 are each independently H or hydrocarbyl; R9 is hydrocarbyl; and each R12 is independently selected from OR13, halo, alkyl, COOR14, CONR15R16, SO2NR17R18, NO2, CN, NR19R20SR21 and CF3, where R13-21 are each independently H, alkyl or aryl; said process comprising the steps of (II) (III) (IV) (i) converting a compound of formula (II) to a compound of formula (III), wherein X is halo and R is aryl, alkyl, cycloalkyl, aralkyl, heteroaryl or alkyl-heteroaryl; (ii) converting said compound of formula (III) to a compound of formula (IV); and (iii) converting said compound of formula (IV) to a compound of formula (I).