To a mixture of 2-(3,4-Dimethoxy-phenyl)-5-(2-piperazin-1-yl-pyrimidin-5-yl)-imidazo[2,1-b][1,3,4]thiadiazole (52 mg, 0.113 mmol, 1 eq), Et3N (0.032 mL, 0.226 mmol, 2 eq), formaldehyde (0.102 mL, 1.36 mmol, 12 eq) and acetic acid (0.02 mL, 0.136 mmol, 1.2 eq) in MeOH (2 mL) was added Sodium cyanoborohydride (0.1 g, 1.58 mmol, 14 eq). The reaction mixture was stirred at rt for 2 h. Solvents were evaporated to dryness and the residue was dissolved in sat NaHCO3/EtOAc. Layers were separated and the aqueous layer was extracted once with EtOAc. The combined organic layers were dried, filtered and evaporated. The residue was purified by HPLC to give the desired product (6 mg, 12%). HPLC-MS: (5-40% B in 8 min, 0.8 mL/min, 50° C.): tR=4.64 min, [M+H]+ m/z 438.2; 1H NMR (300 MHz, DMSO) δ 8.98 (s, 2H), 7.70 (s, 1H), 7.56 (dd, J=8.4, 2.0 Hz, 1H), 7.49 (d, J=2.0 Hz, 1H), 7.16 (d, J=8.5 Hz, 1H), 3.90 (s, 3H), 3.86 (s, 3H), 3.80 (m, 4H), 2.38 (m, 4H), 2.22 (s, 3H).
