4-(Pyrrolidin-1-yl)butan-1-amine → 3-(2,5-Difluoro-4-methyl-benzyloxy)-5-[3-(4-pyrrolidin-1-yl butyl)-ureido]-isothiazole-4-carboxylic acid amide

Participants

Reaction Conditions

Reaction Steps

A mixture of [4-carbamoyl-3-(2,5-difluoro-4-methyl-benzyloxy)-isothiazol-5-yl]-carbamic acid phenyl ester (0.34 g, 0.81 mmol), 4-pyrrolidinobutylamine (0.12 g, 0.81 mmol) and tetrahydrofuran (2.8 mL) was shaken at 45-50° C. for 24 hours. The mixture was concentrated and purified by radial chromatography (4 mm plate, CH3OH—CHCl3—NH4OH (10:89:1) to (15:84:1)), affording 0.31 g of the title compound as a colorless solid. The material was dissolved in ca. 10 mL of 4:1 methanol-chloroform at −10° C. and was treated with a solution of methanesulfonic acid (0.043 mL in 0.5 mL of CH3OH). After stirring for 5 minutes, the mixture was concentrated in vacuo, and the residue was triturated with methanol-ether, affording 0.35 g of the title compound (82%) as a colorless solid. HPLC ret. time: 3.3 minutes. 1H NMR (400 MHz, D2O) δ 6.74 (dd, 1H, J=6.0, 9.6 Hz), 6.63 (dd, 1H, J=6.4, 10.4 Hz), 4.61 (s, 2H), 3.44 (m, 2H), 3.05-2.98 (m, 4H), 2.98-2.81 (m, 2H), 2.62 (s, 3H), 1.95-1.93 (m, 4H), 1.83-1.80 (m, 2H), 1.6-1.5 (m, 2H), 1.4-1.3 (m, 2H) ppm; MS (APCl, m/z): 468 [M+H]+.

Provenance & Evidence