Formic Acid → HCID 86724088, compound

Participants

Reaction Conditions

Reaction Steps

To acetic anhydride (5 mL, 53 mmol), was added formic acid (2.83 mL, 75 mmol). The resulting mixture was heated for about 15 min at about 50° C. To this mixture (after cooling to about 0° C.), was added 4-(2,4-dichlorophenyl)-1,3,6,6-tetramethyl-7,8-dihydro-4H-pyrazolo[3,4-e][1,4]thiazepine (50 mg, 0.14 mmol, Ex. D.4). The reaction mixture was stirred, for about 24 h, at rt. Subsequently, 5% aqueous sodium bicarbonate (25 mL) and ethyl acetate (50 mL) were added. The layers were separated and the organic layer was washed with water (25 mL), dried (MgSO4), filtered and concentrated in vacuo. The resulting residue was purified by column chromatography (SiO2, ethyl acetate), to afford 4-(2,4-dichlorophenyl)-1,3,6,6-tetramethyl-4,7-dihydropyrazolo[3,4-e][1,4]thiazepine-8-carbaldehyde (35 mg, 0.09 mmol, 65%), as a white solid. LC-MS (Table 1, Method a) Rt=4.53/4.71 min (rotamers), m/z 384 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 1.30 (3H, s) 1.49 (3 H, s) 1.65 (3 H, br s) 3.58-3.85 (2 H, br s) 3.73 (3 H, s) 5.48 (1 H, s) 7.11 (1 H, br s) 7.20 (1 H, br s) 7.44 (1 H, br s) 8.45 (1 H, s) (Major) 1H NMR (400 MHz, CDCl3) δ ppm 1.17 (3H, br s) 1.34 (3 H, br s) 1.93 (3 H, s) 3.41 (1 H, d, J=14.2 Hz) 3.69 (3 H, s) 3.76 (1 H, d, J=14.2 Hz) 5.54 (1 H, s) 7.12 (1 H, br s) 7.20 (1 H, br s) 7.39 (1 H, br s) 8.23 (1 H, br s) (Minor).

Provenance & Evidence