Acetic Acid → Dimethyl 3-(3-chlorophenoxy)-2-oxopropylphosphonate

Participants

Reaction Conditions

Reaction Steps

A solution of n-butyl lithium (16.0 g) in hexane (160 ml) was added to a stirred solution of dimethyl methylphosphonate (26.9 g) in anhydrous tetrahydrofuran (150 ml) at -60° C. in an atmosphere of nitrogen during 20 minutes. The solution was maintained at -60° C. for a further period of 10 minutes and was then treated with a solution of ethyl 3-chlorophenoxyacetate (23.4 g) in anhydrous tetrahydrofuran (50 ml) at -60° C. during a further period of 10 minutes. This solution was stirred at -60° C. for 90 minutes and then stirred at ambient temperature for 2 hours. The solution was treated with acetic acid (21 ml) and the solvents were evaporated under reduced pressure. Water (60 ml) was added to the residue and the mixture was extracted with diethyl ether. The ethereal solution was washed with water, with aqueous sodium bicarbonate solution (10% w/v) and with water, dried over magnesium sulphate, and evaporated. The resulting residue was left to stand at ambient temperature overnight. The resulting colourless crystals were filtered off, washed with a small volume of diethyl ether, and recrystallised from a mixture of petroleum ether (b.p. 40°-60° C.) and toluene, to give dimethyl 3-(3-chlorophenoxy)-2-oxopropylphosphonate (18.6 g) in the form of colourless needles, m.p. 78°-79° C. [elemental analysis: C, 44.9; H, 5.1; P, 10.7%. C11H14ClO5P requires C, 45.1; H, 4.8; P, 10.6%. νmax 825, 865, 1030, 1160, 1270, 1335, 1600 and 1735 cm-1 ].

Provenance & Evidence