Acetic Acid → tert-butyl[2-(4-{[3-carbamoyl-8-(methylsulfanyl)-1H-pyrazolo[4,3-h]quinazolin-1-yl]methyl}piperidin-1-yl)ethyl]carbamate

Participants

Reaction Steps

To a solution of 8-(methylsulfanyl)-1-(piperidin-4-ylmethyl)-1H-pyrazolo[4,3-h]quinazoline-3-carboxamide 26 mg (0.073 mmol) in methanol (1.5 ml) and DMF (1 ml), acetic acid 13 μl (0.219 mmol), tert-butyl (2-oxoethyl)carbamate 69.6 mg (0.438 mmol) and NaCNBH3 28 mg (0.438 mmol) were added. The mixture was stirred at r.t. for 18 hours, consequently the volatiles were removed in vacuo. The residue was dissolved with ethyl acetate and portioned with water; the organic layer was washed with brine, dried over Na2SO4 and concentrated. The crude was purified by flash chromatography (DCM/MeOH 95/5) to give tert-butyl[2-(4-{[3-carbamoyl-8-(methylsulfanyl)-1H-pyrazolo[4,3-h]quinazolin-1-yl]methyl}piperidin-1-yl)ethyl]carbamate 27 mg as a white solid (75%). LC/MS (254) HPLC method 2 Rt 3.86 min. 1H NMR (401 MHz, DMSO-d6) δ 9.47 (s, 1H), 8.28 (d, J=8.67 Hz, 1H), 7.81 (s, 1H), 7.74 (d, J=8.79 Hz, 1H), 7.54 (br. s., 1H), 6.56 (br. s., 1H), 5.08 (d, J=7.32 Hz, 2H), 2.93-3.05 (m, 2H), 2.76-2.84 (m, J=10.25 Hz, 2H), 2.71 (s, 3H), 2.27 (br. s., 1H), 2.14 (br. s., 1H), 1.75-1.94 (m, 2H), 1.12-1.49 (m, 17H). HRMS (ESI) calcd for C24H33N7O3S [M+H]+ 500.2439 found 500.2436.

Provenance & Evidence