反应详情

Add hydrogen peroxide (30% in water, 8.73 g, 257 mmol) to 3-amino-3-(3-fluoro-4-methoxyphenyl)-thioacrylamide (29.0 g, 128 mmol) in methanol (1,283 mL) and stir the reaction mixture at room temperature. Quench the reaction with Na2S2O3 (20% in water) and concentrate to dryness. Dilute with EtOAc (900 mL) and water (900 mL), collect the organic phase, and evaporate. Crystallize from EtOAc/hexanes to afford 3-(3-fluoro-4-methoxyphenyl)isothiazol-5-ylamine (1 g). Chromatography of the mother liquor (25 g) over silica gel, eluting with 25-50% EtOAc in hexane, affords additional product. [In one instance, a column loading accident led to loss of ½ of the material; but additional clean material was recovered from the chromatography (1 g).] Yield: 12.2%. ES-MS: m/e 225.0 (m+1).

1. customQuench
2. customthe reaction with Na2S2O3 (20% in water)
3. concentrationconcentrate to dryness
4. additionDilute with EtOAc (900 mL) and water (900 mL)
5. customcollect the organic phase
6. customevaporate
7. customCrystallize from EtOAc/hexanes