Trimethyl phosphite → (9-Anthracenylmethyl)phosphonic acid dimethyl ester

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Reaction Steps

A solution of 9-(chloromethyl)anthracene (2.5 g, 0.011 M) in trimethylphosphite (5 mL, 5.26 g, 0.042 M) is heated at reflux temperature for 72 hours. Excess trimethylphosphite is removed under reduced pressure and the residue is chromatographed over silica gel (400 g, 40-63 μm, CH2Cl2, 50 mL fractions) using CH2Cl2 (60 fractions) and 2% CH3OH in CH2Cl2 for the remaining fractions. Fractions 86-93 (2.99 g) are found to contain desired material and an impurity and are rechromatographed (400 g silica gel, 40-63 μm, CH2Cl2, 50 mL fractions) using 2.5% acetone-CH2Cl2 to elute the column. Fractions 100-160 contains compound (1.495 g, 0.00498 M, 45%) as a yellow solid. Crystallization from ethyl acetate gives the title compound (1.34 g) as yellow needles, mp 152°-153° C.

Provenance & Evidence