Potassium tert-butoxide → (2'R,6'S)-3,3''-dimethyl-1'-[2-(1H-pyrazol-4-yl)-ethyl]-1',2',3',4'5',6'-hexahydro-[2,2';6',2'']terpyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of (2′R,6′S)-1′-[2-(2-benzyl-1 H-pyrazol-4-yl)-ethyl]-3,3″-dimethyl-1′,2′,3′,4′,5′,6′-hexahydro-[2,2′;6′,2″]terpyridine (0.130 g, 0.288 mmol) in dry DMSO (0.70 mL) and THF (12 mL) was added 4 Å molecular sieve (˜1 g) pre-heated at 140° C., and KOtBu (0.600 g, 5.35 mmol). The solution was bubbled with air (pre-dried by passing through a NaOH column) at room temperature for 1 h. Saturated aqueous NH4Cl (20 mL) was then added. The mixture was filtered through a celite cake and the cake was washed with EtOAc throughout. The organic layer in the filtrate was collected, and the aqueous layer was extracted with CH2Cl2 (3×30 mL). The extracts were combined and dried over Na2SO4. After filtration the solvent was removed by evaporation under vacuum, and the residue was purified by flash chromatography on a silica gel column (200:10:1 CH2Cl2/CH3OH/NH4OH), affording a pale yellow solid (0.067 g, 64%) after precipitation from CH2Cl2/hexanes by evaporation under vacuum. 1HNMR(CDCl3) δ 1.60-1.85 (4H), 2.00-2.15 (m, 2H), 2.25-2.62 (m, 10H), 4.10-4.20 (m, 2H), 6.73 (s, 2H), 7.07-7.12 (m, 2H), 7.43 (d, 2H, J=7.2 Hz), 8.45 (s, br. 2H); 13C NMR (CD2Cl2) δ 19.02, 21.33, 25.61, 30.31, 50.86, 64.12, 118.85, 122.40, 132.22, 132.65, 138.78, 147.03, 160.46. ES-MS m/z 362 (M+H). Anal. Calcd. for C22H27N5.0.2H2O: C, 72.38; H, 7.56; N, 19.18. Found: C, 72.31; H, 7.70; N, 18.98.

Provenance & Evidence