To solution of 2-chloro-4-morpholin-4-yl-thieno[3,2-d]pyrimidine 4 (1.22 g) in anhydrous tetrahydrofuran (20 ml) stirring at −78° C. was added 2.5M n-butyllithium in hexanes (2.3 mL). The reaction mixture was warmed gradually to −40° C. over 1 hour, cooled to −78° C., and 1-BOC-4-Piperidone (950 mg) was added. The reaction mixture was gradually warmed to room temperature and then left to stir for 2 hours, poured into ice/water and extracted into ethyl acetate. After the usual drying and evaporation of the solvent, the residue was purified by flash chromatography to give 4-(2-chloro-4-morpholin-4-yl-thieno[3,2-d]pyrimidin-6-yl)-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester.
