Sulfuric Acid → HCID 9841373, compound

Participants

Reaction Steps

To an ice-cooled suspension of 3-(1-hydroxy- 1-phenylmethyl)-5-[1-(2-pyridyl)piperazin-4-yl]-1,2,4-thiadiazole (0.625 g, 1.77 mmol) in acetone was added dropwise over a period of ca. 10 min a solution of chromium trioxide (0.15 g, 1.5 mmol) dissolved in water (12 mL) and conc. sulfuric acid (0.33 mL). The resulting mixture was allowed to warm to room temperature and stirred for 16 h. The reaction mixture was diluted with ethyl acetate (100 mL), then made basic (pH ca. 10) by the addition of 3N sodium hydroxide solution. The organic layer was collected, washed with water, dried (sodium sulfate), filtered and concentrated in vacuo. Purification by column chromatography on silica gel using a solvent gradient of a mixture of hexane and ethyl acetate (6/4 and 4/6) afforded the title compound (390 mg, 75.3%) as a light yellow solid. The starting material (101 mg, 16.2%) was also recovered. M.p. 109.5-111.0° C.; 1H-NMR (CDCl3) δ8.23-8.26 (m, 3H), 7.50-7.63 (m, 4H), 6.73-6.74 (m, 2H), 3.79 (m, 8H, 4CH2); MS m/z 352 (M+ +1), 309, 258, 232, 204,147, 121,104, 77.

Provenance & Evidence