Acetic Acid → 2-(3,4-Dimethoxy-phenyl)-5-[6-(4-methyl-piperazin-1-yl)-5-trifluoromethyl-pyridin-3-yl]-imidazo[2,1-b][1,3,4]thiadiazole

Participants

Reaction Steps

To a mixture of 2-(3,4-Dimethoxy-phenyl)-5-(6-piperazin-1-yl-5-trifluoromethyl-pyridin-3-yl)-imidazo[2,1-b][1,3,4]thiadiazole (105 mg, 0.199 mmol, 1 eq), Et3N (0.056 mL, 0.399 mmol, 2 eq), formaldehyde (0.180 mL, 2.39 mmol, 12 eq) and acetic acid (0.02 mL, 0.239 mmol, 1.2 eq) in MeOH (4 mL) was added Sodium cyanoborohydride (0.175 g, 2.79 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 on silica gel (isolute flash Si II, 10 g, 96:4 DCM/7N NH3 in MeOH) to give the desired product (50 mg, 50%). HPLC-MS: (5-100% B in 8 min, 0.8 mL/min, 50° C.): tR=3.47 min, [M+H]+ m/z 505.3; 1H NMR (300 MHz, CDCl3) δ 8.92 (s, 1H), 8.49 (d, J=1.9 Hz, 1H), 7.52 (s, 1H), 7.42 (d, J=1.7 Hz, 1H), 7.36 (dd, J=8.3, 2.0 Hz, 1H), 6.90 (d, J=8.4 Hz, 1H), 3.94 (s, 3H), 3.88 (s, 3H), 3.41 (m, 4H), 2.57 (m, 4H), 2.34 (s, 3H).

Provenance & Evidence