Acetic Acid → Dimethyl 2-Oxo-3-methylheptylphosphonate

Temperature

-60 °C

A stirred solution of dimethyl methylphosphonate (54 g.) in dry tetrahydrofuran (390 ml.) at -45° to -50° C. was treated, dropwise during 20 minutes, with a solution of butyl lithium (32 g.) in pentane (250 ml.). Stirring was continued at that temperature for a further 10 minutes, and then the mixture was cooled to -60° C. and treated, dropwise during 15 minutes, with a solution of ethyl 2-methylhexanoate (34.5 g.) in tetrahydrofuran (120 ml.). The mixture was stirred at -60° C. for a further 90 minutes and then at room temperature for 3 hours, and then it was treated with acetic acid (42 ml.), evaporated to dryness in vacuo, and the residue treated with water (170 ml.). The mixture was extracted twice with diethyl ether and the combined ethereal extracts washed with water, dried over sodium sulphate and evaporated to dryness in vacuo. The residue was distilled to give dimethyl 3-methyl-2-oxoheptylphosphonate (16.8 g.), b.p. 93-94° C./0.2 mm.Hg.

1. stirringThe mixture was stirred at -60° C. for a further 90 minutes
2. waitat room temperature for 3 hours
3. customevaporated to dryness in vacuo
4. additionthe residue treated with water (170 ml.)
5. extractionThe mixture was extracted twice with diethyl ether
6. washthe combined ethereal extracts washed with water
7. dry with materialdried over sodium sulphate
8. customevaporated to dryness in vacuo
9. distillationThe residue was distilled

ORD record

ord-6b5dc8e3ecda438f92757fcce2cbfcd0

Source dataset

uspto-grants-1978_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04088821