Reaktion #2066

Reaktionsgleichung

N-methoxy-N-methyl-3,3-bis(diethoxyphosphinyl)propionamide

sodium hydride

THF

THF

hydride

→

title compound

Ausbeute 54.0%

tetraethyl 3-oxopentane-1,1-bisphosphonate

Ausbeute 54.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas consumed (~20 minutes)
2. 2
   workup.ADDITIONethylmagnesium bromide (1.0 ml of a 3.0M solution in diethyl ether, 3.0 mmol) was added
3. 3
   workup.ADDITIONAfter the addition
4. 4
   Temperaturthe reaction mixture was warmed to 0° C.
5. 5
   workup.STIRRINGstirred for one hour
6. 6
   SonstigeThe reaction was quenched
7. 7
   workup.ADDITIONby pouring slowly into a well-stirred ice-cold mixture of ethanol (40 ml) and concentrated HCl (5 ml)
8. 8
   SonstigeThe solvents were removed in vacuo
9. 9
   Extraktionextracted with dichloromethane (4×20 ml)
10. 10
    TrocknenThe combined extracts were dried (Na2SO4)
11. 11
    Einengenconcentrated in vacuo
12. 12
    Sonstigethe resulting oil was purified by flash chromatography on silica gel eluting with 10% i-propanol in ethyl acetate

Vorschrift

A solution of N-methoxy-N-methyl-3,3-bis(diethoxyphosphinyl)propionamide (1.00 g, 2.6 mmol) in THF (5 ml) was slowly added to a slurry of 80% sodium hydride (80 mg, 2.7 mmol) in THF (10 ml) at 0° C. Stirring was continued until all of the hydride was consumed (~20 minutes). The solution was cooled to -78° C. and ethylmagnesium bromide (1.0 ml of a 3.0M solution in diethyl ether, 3.0 mmol) was added. After the addition, the reaction mixture was warmed to 0° C. and stirred for one hour. The reaction was quenched by pouring slowly into a well-stirred ice-cold mixture of ethanol (40 ml) and concentrated HCl (5 ml). The solvents were removed in vacuo, the residue was taken up in brine (20 ml) and extracted with dichloromethane (4×20 ml). The combined extracts were dried (Na2SO4), concentrated in vacuo, and the resulting oil was purified by flash chromatography on silica gel eluting with 10% i-propanol in ethyl acetate to give the title compound (0.50 g, 54%) as a pale yellow oil.

Quelle