Ytterbium triflate → 2-(4-{3-[5-Acetyl-3-(4-trifluoromethyl-phenyl)-4,5,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-1-yl]-2-hydroxy-propyl}-piperazin-1-yl)-benzonitrile

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Reaction Steps

A solution of 1-[1-oxiranylmethyl-3-(4-trifluoromethyl-phenyl)-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl]-ethanone (0.84 g, 2.30 mmol) in CH2Cl2 (10 mL) was treated with ytterbium(III) triflate (0.29 g, 0.46 mmol) and 1-(2-cyanophenyl)-piperazine (0.75 g, 3.5 mmol) at 25° C. and stirred for 48 h before it was diluted with CH2Cl2 (100 mL) and H2O (50 mL). The organic layer was separated, washed with H2O (2×50 mL), dried over Na2SO4, and concentrated. Column chromatography (silica, 5% MeOH/CH2Cl2) afforded 1.15 g (90%) of light yellow crystals. TLC (silica, 10% MeOH/CH2Cl2): Rf=0.30. MS (electrospray): m/z 553.3 ([M+H]+, C29H31F3N6O2 requires 552.3). 1H NMR (CDCl3, 400 MHz, a mixture of two rotamers): 7.82 and 7.68 (AB pattern, Jab=8.2 Hz, 2H), 7.76 and 7.72 (AB pattern, Jab=8.4 Hz, 2H), 7.60-7.48 (m, 2H), 7.05-7.00 (m, 2H), 4.90 and 4.78 (AB pattern, Jab=16 Hz, 1H), 4.69 (s, 1H), 4.30-3.71 (m, 6H), 3.25 (m, 4H), 3.02-2.75 (m, 4H), 2.70-2.65 (m, 2H), 2.60-2.53 (m, 2H), 2.23 (s, 1.5H), 2.18 (s, 1.5H).

Provenance & Evidence