Sodium borohydride → HCID 12096237, compound

7-bromo-2-(1,1-dimethylethyl)-2,3-dihydro-1,2-benzisothiazol-3-ol 1,1-dioxide (1.4 g, 4.4 mmol) was treated with formic acid (10 mL). The reaction was stirred at ambient temperature over 18 h, concentrated in vacuo and dissolved in methanol (10 mL). The mixture was cooled to 0° C. and treated with sodium borohydride (0.17 g, 4.4 mmol) in small portions over 20 min. The cooling bath was removed and the resulting reaction mixture stirred at ambient temperature over 18 h. The work-up consisted of slowly quenching the reaction mixture with ice, dilution with water and extraction with ethyl acetate. Drying over sodium sulfate and concentrating under reduced pressure provided the crude product that was purified by a plug of silica gel (ethyl acetate/hexane, 1:4) to afford the desired 7-bromo-2,3-dihydro-1,2-benzisothiazole 1,1-dioxide (0.6 g, 60% over 2 steps). 1H NMR (CD3OD): δ 4.40 (s, 2H), 7.53 (m, 2H), 7.70 (m, 1H).

1. concentrationconcentrated in vacuo
2. dissolutiondissolved in methanol (10 mL)
3. temperatureThe mixture was cooled to 0° C.
4. customThe cooling bath was removed
5. customthe resulting reaction mixture
6. stirringstirred at ambient temperature over 18 h
7. customof slowly quenching the reaction mixture with ice, dilution
8. extractionwith water and extraction with ethyl acetate
9. dry with materialDrying over sodium sulfate
10. concentrationconcentrating under reduced pressure
11. customprovided the crude product that
12. customwas purified by a plug of silica gel (ethyl acetate/hexane, 1:4)

ORD record

ord-f56605e438564dce8c22865dbdf3b224

Source dataset

uspto-grants-2004_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06689770B2