Methyl iodide → Dimethyl (1,1-diethoxyethyl)phosphine oxide

Temperature

-78 °C

To a solution of methyl(1,1-diethoxyethyl)phosphine oxide, prepared as described in EP 0 501 702 (89.3 g, 0.5 mol) in THF (900 ml) at -78° C. under an atmosphere of argon is added a solution of potassium bis(trimethylsilyl)amide (688 ml, 0.521 mol) in toluene over 15 minutes. After stirring for 1 hour at -78° C., methyl iodide (34 ml, 0.55 mol) is added over 5 minutes and stirring at -78° C. continued for 1 hour. The reaction is then quenched by the addition of a 1% solution of NaH2PO4 (450 ml) and slow warming to room temperature. Concentration gives an aqueous suspension to which dichloromethane (600 ml) is added. The organic phase is separated and washed with 1% NaH2PO4 (500 ml), followed by water (500 ml). Drying over MgSO4, concentration and purification by flash vacuum silica column chromatography (chloroform-ethanol 40:1) gives a clear oil which is distilled to give dimethyl (1,1-diethoxyethyl)phosphine oxide. b.p. 100° C. at 0.05 mmHg.

1. stirringstirring at -78° C.
2. waitcontinued for 1 hour
3. customThe reaction is then quenched by the addition of a 1% solution of NaH2PO4 (450 ml)
4. temperatureslow warming to room temperature
5. concentrationConcentration
6. customgives an aqueous suspension to which dichloromethane (600 ml)
7. additionis added
8. customThe organic phase is separated
9. washwashed with 1% NaH2PO4 (500 ml)
10. dry with materialDrying over MgSO4, concentration and purification by flash vacuum silica column chromatography (chloroform-ethanol 40:1)
11. customgives a clear oil which
12. distillationis distilled

ORD record

ord-bc435b38201a44b9b4423c35391248db

Source dataset

uspto-grants-1999_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05952478