Dimethyl methylphosphonate → Dimethyl 3-cyclohexyl-2-oxobutylphosphonate

Temperature

0 °C

74.5 g. of dimethyl methylphosphonate were dissolved in 514 ml. of tetrahydrofuran and the solution cooled to -60°C. To this solution a solution of butyllithium [prepared from 40.5 g. of butyl bromide and 9.2 g. of lithium] in 240 ml. of diethyl ether was added dropwise. A solution of 39.5 g. of ethyl 2-cyclohexylpropionate in 130 ml. of tetrahydrofuran was added drop-wise and the mixture stirred at the same temperature for two hours and afterwards at 0°C. overnight. The reaction mixture was then neutralised to pH 7 with acetic acid, concentrated under reduced pressure and, after the addition of water to the residue, extracted with diethyl ether. After drying the ethereal extract, the solvent was distilled off and the residue subjected to distillation under reduced pressure to obtain 40 g. (yield 30.2%) of the title compound as a colourless oil, b.p. 140°C./0.2-0.3 mm.Hg. Nuclear magnetic resonance (hereinafter abbreviated to NMR) spectrum (tetrachloromethane): δ = 3.82 (6 H, doublet, 3.18 (2H, doublet), 2.80 - 2.30 (1H, multiplet), 2.1 - 0.65 (14H, multiplet).

1. concentrationconcentrated under reduced pressure
2. additionafter the addition of water to the residue
3. extractionextracted with diethyl ether
4. customAfter drying the ethereal
5. extractionextract
6. distillationthe solvent was distilled off
7. distillationthe residue subjected to distillation under reduced pressure
8. customto obtain 40 g

ORD record

ord-12ba17f3624e4f4fa1c33849d7cf4042

Source dataset

uspto-grants-1976_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03966792