Trifluoroacetic acid → Ethyl acetate methanol ammonia

Participants

Reaction Steps

(2S) N-Cyclopropylmethyl-N-[1-(4-methyl-2-methylamino-pentanoyl)piperidin-4-yl]-3-trifluoromethylbenzenesulfonamide fumarate (7): Methyl-{3-methyl-1-[4-(3-trifluoromethylbenzenesulfonylamino)piperidine-1-carbonyl]butyl}-carbamic acid tert-butyl ester (3) (0.5 g, 0.93 mmol) was alkylated with cyclopropylmethyl bromide using method B. The product was treated with trifluoroacetic acid and worked up according to method B. Flash chromatography (SiO2, ethyl acetate:methanol:ammonia 250:20:2) gave the free base as a colourless gum (88 mg). This gum was converted to the fumarate salt to give the title compound (7) (80 mg, 14%) as a white solid. TLC (SiO2, ethyl acetate: methanol: ammonia, 250:40:4): Rf=0.31 (detection UV and potassium iodoplatinate). LC: 100%. MS (m/z): 490.2, 491.2 (M+H). 1H NMR (400 MHz, DMSO-d6): δ 8.20 (1H, d, J=7 Hz), 8.12 (1H, s), 8.07 (1H, d, J=7 Hz), 7.85 (1H, t, J=7 Hz), 6.56 (2H, s), 4.45 (1H, m), 4.00-3.05 (5H, m), 2.65 (2H, m), 2.30 and 2.22 (3H, 2s), 1.73-1.48 (5H, m), 1.35 (2H, m), 0.95 (1H, m), 0.85 (6H, m), 0.45 (2H, m), 0.25 (2H, m).

Provenance & Evidence