(Diethylamino)sulfur trifluoride → 3-Methyl-7-propyl-1,2-benzisoxazol-6-ol

Participants

Reaction Conditions

Reaction Steps

1-(2,4-dihydroxy-3-propylphenyl)ethanone oxime (400 mg, 1.91 mmol) (Example 66) was dissolved in CH2Cl2 and the solution was cooled to −35° C. under an atmosphere of argon. (Diethylamino)sulfur trifluoride (DAST) (647 mg, 4.01 mmol) was added dropwise and the solution was allowed to warm to −25° C. over 2 h. The mixture was quenched with NaHCO3 (saturated aqueous solution). The organic phase separated and the aqueous phase extracted with CH2Cl2. The combined organic phases were dried over Na2SO4, filtered, and concentrated under reduced pressure. Purification by silica gel flash chromatography (EtOAc/hexane (v/v)=1:3) gave 282 mg (77%) of the title compound as a faintly red-colored solid. 1H NMR (400 MHz, CDCl3): δ 0.95 (t, 3H), 1.67 (m, 2H), 2.56 (s, 3H), 2.79 (t, 2H), 6.76 (d, 1H), 7.19 (d, 1H).

Provenance & Evidence