Hydrochloric Acid → 6-[2-(3-Chloro-4-isopropoxy-phenyl)-ethyl]-6-cyclopentyl-3-(5,7-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-2-ylmethyl)-4-hydroxy-5,6-dihydro-pyran-2-one

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Reaction Steps

6-[2-(3-Chloro-4-isopropoxy-phenyl)-ethyl]-6-cyclopentyl-dihydro-pyran-2,4-dione (0.3 g, 0.79 mmol) and 5,7-Dimethyl-[1,2,4]triazolo[1,5-a]pyrimidine-2-carbaldehyde (0.17 g, 0.95 mmol, described in Step 3 of example B(75)) were dissolved in 3:1 MeOH/CH2Cl2 (4 mL). To this suspension, Me2NH.BH3 (0.07 g, 1.19 mmol) was added as a solid from top. After stirring 1 h at room temperature, the reaction mixture became clear and it was stirred for an additional 5 hours. After this time, 1 M HCl (1 mL) was added and the reaction stirred for 30 minutes at room temperature, the solvent was the evaporated to half the volumen and extracted 3 times with 10% MeOH/CH2Cl2 (10 mL). The organic phase was dried over MgSO4 and evaporated. The residue purified by flash column chromatography (80% EtOAc in hexanes) to eliminate unreacted pyrone and reduced 5,7-Dimethyl-[1,2,4]triazolo[1,5-a]pyrimidine-2-carbaldehyde, then 3% MeOH/CH2Cl2 to give the product (0.1 g, 24%) as a white solid. 1H NMR (DMSO-d6): δ 1.14 (d, J=6.3, 6H), 1.4-1.53 (m, 8H), 1.7-1.75 (m, 2H), 1.95-1.98 (m, 1H), 2.35-2.44 (m, 8H), 3.19 (s, 2H), 3.57 (d, J=16 Hz, 1H), 3.69 (d, J=16 Hz, 1H), 4.41-4.47 (m, 1H), 6.91-6.93 (s, 1H), 7-7.07 (m, 2H), 7.10 (d, J=2.0, 1H), 10.7 (brs, 1H). Anal. Calcd. For C29H35N4O4: C, 64.61; H, 6.54; N, 10.39. Found: C, 64.30; H, 6.81; N, 10.35. ESIMS (MH+): 540

Provenance & Evidence