Synthesis of 3-(4-Chloro-2-methoxy-7H-pyrrolo[2,3-d]-pyrimidin-7-yl)propanoic acid – An N(9)-Functionalized 7-Deazapurine

Regioselective N-alkylation of 4-chloro-2-methoxy-7H-pyrrolo[2,3- d]pyrimidine (6) with ethyl 3-bromopropionate under liquid-liquid phase-transfer reactionconditions gave the ester 7a. Its saponification yielded the acid 7b. The logP values of a series of N(9)-functionalized purines and purine isosteres were calculated.