Tert-butyl 4-(chlorocarbonyl)piperazine-1-carboxylate → Tert-butyl 4-(3-(4-(3,4-difluoro-2-(trifluoro-methyl)phenyl)piperidine-1-carbonyl)-1,4,5,6-tetrahydro-pyrrolo[3,4-c]pyrazole-5-carbonyl)piperazine-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of (4-(3,4-difluoro-2-(trifluoromethyl)phenyl)piperidin-1-yl)(1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazol-3-yl) methanone hydrochloride salt (50 mg, 0.11 mmol), N,N,N-diisopropylethylamine (0.05 mL, 0.3 mmol) and DMAP (0.5 mg, 0.004 mmol) in anhydrous CH2Cl2 (1 mL) was cooled to 0° C. under an atmosphere of N2, treated with tert-butyl 4-(chlorocarbonyl)piperazine-1-carboxylate (30 mg, 0.12 mmol) and stirred at 0° C. for 1 h. The cooling bath was then removed and the reaction stirred at room temperature for a further 4 h. After this time, the mixture was chromatographed over silica gel (Isco CombiFlash Rf unit, 12 g Redisep gold column, 0% to 10% CH3OH in CH2Cl2) to provide tert-butyl 4-(3-(4-(3,4-difluoro-2-(trifluoromethyl)phenyl)piperidine-1-carbonyl)-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole-5-carbonyl)piperazine-1-carboxylate as a white solid (48 mg, 71%): 1H NMR (500 MHz, CDCl3) δ 10.76 (br s, 1H), 7.33 (dd, J=17.0, 9.0 Hz, 1H), 7.11 (dd, J=9.0, 4.0 Hz, 1H), 4.88-4.52 (m, 2H), 4.69 (br s, 2H), 4.62 (s, 2H), 3.49 (apparent t, J=4.5 Hz, 4H), 3.32 (apparent t, J=4.5 Hz, 4H), 3.25 (apparent t, J=12.5 Hz, 1H), 3.14-2.88 (m, 2H), 1.94 (d, J=12.5 Hz, 2H), 1.72-1.66 (m, 2H), 1.48 (s, 9H).

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