Triethylamine → 5-Chloropyrazine-2-carboxylic acid 2-benzyloxy-1-benzyloxymethyl-ethyl ester

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Reaction Conditions

Reaction Steps

A suspension of 5-chloro-pyrazine-2-carboxylic acid (prepared as in Example 29, 1.00 g, 6.33 mmol) in methylene chloride (30 mL) was treated with 1,3-dibenzyloxy-2-propanol (2.06 g, 7.57 mmol), bis(2-oxo-3-oxazolidinyl)phosphinic chloride (1.61 g, 6.34 mmol), and triethylamine (1.83 mL, 12.66 mmol). The mixture was stirred at 25° C. overnight. The solution was extracted with methylene chloride and a saturated aqueous sodium bicarbonate solution. The organic layer was washed with water, a saturated aqueous sodium chloride solution, a 1N aqueous hydrochloric acid solution, and a saturated aqueous sodium chloride solution. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40L, Silica, 3/1 hexanes/ethyl acetate) afforded the 5-chloropyrazine-2-carboxylic acid 2-benzyloxy-1-benzyloxymethyl-ethyl ester (1.45 g, 55.7%) as a colorless oil.

Provenance & Evidence