Hydrogen Peroxide → 6-Ethoxy-3,4-difluoronaphthalen-2-ol

HRID 1873323Notes

Reaction equation

[CH2:1]([O:3][C:4]1[CH:13]=[C:12]2[C:7]([CH:8]=[CH:9][C:10]([F:15])=[C:11]2[F:14])=[CH:6][CH:5]=1)[CH3:2].[Li]CCCC.B(OC)(OC)[O:22]C.OO>C1COCC1.S([O-])([O-])(=O)=O.[Fe+2].[NH4+].O.C(O)(=O)C>[CH2:1]([O:3][C:4]1[CH:13]=[C:12]2[C:7](=[CH:6][CH:5]=1)[CH:8]=[C:9]([OH:22])[C:10]([F:15])=[C:11]2[F:14])[CH3:2]

Participants

Conditions

Temperature: -10 °C

Procedure

30.0 g (about 0.1 mol) of 7-ethoxy-1,2-difluoronaphthalene are initially introduced in 300 ml of THF, and 130.0 ml (0.21 mol) of n-BuLi (15% soln. in hexane) are added at −75° C. After 1 h at this temperature, 25.0 ml (0.22 mol) of trimethyl borate are added dropwise, and the batch is warmed to −10° C. 50 ml of dilute acetic acid (about 30%) are added, and the mixture is warmed to 30° C. 40 ml of hydrogen peroxide solution (35%) are carefully added, and the mixture is stirred vigorously for 18 h. Water is added, and ammonium iron(II) sulfate is added to the batch. The solution is extracted a number of times with MTBE, and the combined organic phases are washed successively with water and sat. sodium chloride soln. The solution is dried using sodium sulfate and evaporated to dryness. The crude product is purified by column chromatography (SiO2, toluene:ethyl acetate=9:1), giving 6-ethoxy-3,4-difluoronaphthalen-2-ol as a pale-brown solid.

Workup

temperaturethe mixture is warmed to 30° C
extractionThe solution is extracted a number of times with MTBE
washthe combined organic phases are washed successively with water and sat. sodium chloride soln
customThe solution is dried
customevaporated to dryness
customThe crude product is purified by column chromatography (SiO2, toluene:ethyl acetate=9:1)

Sources & evidence

ORD record: ord-b00505e4a8ad46ac9c56f2d4f53dec5d
Source dataset: uspto-grants-2012_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08303844B2

Reaction notes

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