[5-(2-Amino-ethyl)-thiazol-2-yl]-carbamic acid tert-butyl ester (compound 14.1; 20.5 mmol), compound 6.2 (0.94 equivalent) and DIEA (1.0 equivalent) was heated in N,N-dimethylformamide (“DMF”; 75 mL) at 90° C. for 1.5 hours. The reaction mixture was cooled and diluted with EtOAc and water. The organic layer was separated, washed with brine, dried, concentrated and purified by flash column chromatography on silica gel to provide {5-[2-(thieno[3,2-d]pyrimidin-4-ylamino)-ethyl]-thiazol-2-yl}-carbamic acid tert-butyl ester (compound 14.2) in 75% yield.
