Sodium Bicarbonate → HCID 21928208, compound

Participants

Reaction Steps

The obtained 6-acetamido-3-[2-[2-(2,4-dichlorophenyl)-5-isopropyl-4-oxazolyl]ethyl]-1,2-benzisoxazole (900 mg, 1.96 mmol) was reacted in 3N hydrochloric acid (45 mL) at 100° C. for 4 hours. The reaction mixture was allowed to room temperature, neutralized with a saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The organic layer was washed with saline, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to give 6-amino-3-[2-[2-(2,4-dichlorophenyl)-5-isopropyl-4-oxazolyl]ethyl]-1,2-benzisoxazole (770 mg) as brown oil in the residue. The product (770 mg, 1.85 mmol) was suspended in 25% sulfuric acid (9.3 mL), and cooled with ice. An aqueous sodium nitrite solution (166 mg, 2.41 mmol/1.3 ml) was dropwise added to the suspension for 5 minutes. The resulting solution was stirred for 45 minutes under the same conditions. The reaction mixture was dropwise added to a 75% sulfuric acid (7.4 mL) while refluxing for 5 minutes, and the mixture was refluxed for 4 hours. The reaction mixture was left to get cool, extracted with diethyl ether, washed with a saturated aqueous ammonium chloride solution and saline, and dried over anhydrous sodium sulfate. Diethyl ether was removed under reduced pressure. The residue was purified by column chromatography on silica gel with hexane/ethyl acetate (3/1) to give the desired compound (138 mg) as pale yellow oil (yield of the two steps 17%).

Provenance & Evidence