Triethylamine → 5-Ethoxycarbonyl-2-methoxy-2-oxo-1,3,2-benzo-dioxaphosphole

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Reaction Steps

Triethylamine (2.211 g, 21.86 mM) was added to a solution of1.989 g (10.93 mM) of ethyl 3,4-dihydroxybenzoate in 30 ml of ether. The mixture was cooled to -30° C. to -20° C. and a solution of 1.627 g (10.93 mM) of methyl dichlorophosphate in 10 ml of ether was added thereto dropwise with stirring over 10 minutes. The reaction mixture was stirred at the same temperature for 5 minutes, the bath was then removed and the temperature was allowed to rise to 20° C. Filtration and washing were carried out by the procedure of Reference Example 1, and the filtrate and washings were concentrated at room temperature (20°~25° C.) under reduced pressure. There was obtained 2.387 g (84.6% yield) of 5-ethoxycarbonyl-2-methoxy-2-oxo-1,3,2-benzo-dioxaphosphole as a viscous oil.

Provenance & Evidence