Benzyl Bromide → Tert.butyl(benzyl)(diethoxymethyl)phosphine oxide

HRID 36456Notes

Reaction equation

[C:1]([PH:5](=[O:13])[CH:6]([O:10][CH2:11][CH3:12])[O:7][CH2:8][CH3:9])([CH3:4])([CH3:3])[CH3:2].C([Li])CCC.[CH2:19](Br)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.[Cl-].[NH4+]>O1CCCC1>[C:1]([P:5](=[O:13])([CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[CH:6]([O:10][CH2:11][CH3:12])[O:7][CH2:8][CH3:9])([CH3:3])([CH3:2])[CH3:4]

Participants

Conditions

Temperature: -78 °C

Procedure

Tertiary-butyl(diethoxymethyl)phosphine oxide (2.5 g), (0.012 mol) is dissolved in 35 ml of dry tetrahydrofuran and cooled to -78° C. under an argon atmosphere. To this stirred solution is added 9.0 ml of n-butyl lithium (1.6M solution in hexane) and the mixture is stirred at -78° C. for 10 minutes. After this time, a solution of 2.47 g (0.014 mol) of benzyl bromide in 15 ml of dry tetrahydrofuran is added, and the reaction mixture is allowed to warm to room temperature. After stirring for 3 hours at room temperature, 10 ml of saturated ammonium chloride solution is added and the product is extracted into diethyl ether (2×100 ml). The combined organic extracts are dried and evaporated under reduced pressure to give a crude product. This is purified by chromatography on silica, using ethyl acetate as eluent, to give tertiary-butyl(benzyl)(diethoxymethyl) phosphine oxide as a colourless oil.

Workup

temperatureto warm to room temperature
stirringAfter stirring for 3 hours at room temperature
extractionthe product is extracted into diethyl ether (2×100 ml)
customThe combined organic extracts are dried
customevaporated under reduced pressure
customto give a crude product
customThis is purified by chromatography on silica

Sources & evidence

ORD record: ord-baa62213048349e786b517c85532daf9
Source dataset: uspto-grants-1995_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05414133

Reaction notes

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