To suspension of N-[3-({4-[(4-tert-butyl-1,3-thiazol-2(3H)-ylidene)(cyano)methyl]pyrimidin-2-yl}amino)propyl]acetamide (290 mg, 0.68 mmol) in THF (7 ml) were added potassium tert-butoxide (91 mg, 0.81 mmol) and methyl iodide (0.085 mL, 1.35 mmol). The resulting mixture was stirred 2 h at rt. LC/MS analysis showed the presence two peaks with the same mass in a proportion of 7:3. The THF was evaporated and the residue was taken up in water and extracted with EtOAc (3×). The combined organic layer was washed with brine, dried with MgSO4 and the solvent was evaporated under reduced pressure to give a gummy residue which was the mixture of to compounds of the same mass. It was taken up in DCM and an excess TFA then ether were added to the solution. As no precipitation occurred, the solution was concentrated under reduced pressure and the residue was purified by preparative HPLC to give 93 mg of the title compound as a TFA salt pyrimidine (yellow solid, Y=27.3%).
