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

HRID 603406Notes

Reaction equation

O[C:2]1[C:7]([CH2:8][CH2:9][CH3:10])=[C:6]([OH:11])[CH:5]=[CH:4][C:3]=1[C:12](=[N:14][OH:15])[CH3:13].C(N(S(F)(F)F)CC)C>C(Cl)Cl>[CH3:13][C:12]1[C:3]2[CH:4]=[CH:5][C:6]([OH:11])=[C:7]([CH2:8][CH2:9][CH3:10])[C:2]=2[O:15][N:14]=1

Participants

Conditions

Temperature: -35 °C

Procedure

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).

Workup

temperatureto warm to −25° C. over 2 h
customThe mixture was quenched with NaHCO3 (saturated aqueous solution)
customThe organic phase separated
extractionthe aqueous phase extracted with CH2Cl2
dry with materialThe combined organic phases were dried over Na2SO4
filtrationfiltered
concentrationconcentrated under reduced pressure
customPurification by silica gel flash chromatography (EtOAc/hexane (v/v)=1:3)

Sources & evidence

ORD record: ord-3eb75950c16b4c078b2e3427ec81429f
Source dataset: uspto-grants-2011_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07906653B2

Reaction notes

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