p-Toluenesulfonic acid monohydrate → HCID 131719382, compound

Participants

Reaction Conditions

Reaction Steps

A solution of N-[O-[(1,1-dimethylethyl)dimethylsilyl]-N-[(phenylmethoxy)carbonyl]-L-homoseryl]-O-(2,2-dimethoxyethyl)-L-serine, methyl ester [5.56 g, 10 mmol, prepared as described in Example 10(h)] in methanol (65 ml) was cooled to 0° C. (ice salt bath), treated with p-toluenesulfonic acid monohydrate (386 mg, 2.0 mmol) and stirred at 0° C. for 1.5 hours. The reaction was quenched with sodium bicarbonate solution (198 mg. in 20 ml water), stirred for 5 minutes then evaporated to remove the methanol. The aqueous phase was extracted with ethyl acetate (2×200 ml) and the combined organic extract was washed with water (110 ml), 5% sodium bicarbonate (80 ml) and brine (80 ml), dried (anhydrous sodium sulfate), filtered, evaporated to dryness and dried in vacuo. The crude product was chromatographed on silica gel column (Merck), eluting the column with ethyl acetate:hexane (2:1) and ethyl acetate:methanol (98:2) to give 3.975 g of title product as a syrup. TLC (ethyl acetate:hexane, 4:1) Rf =0.17.

Provenance & Evidence