Ethyl phosphorochloridite → Diethyl 2-[bis(3,5-di-t-butyl-4-methoxyphenyl)phosphino]phenylphosphonite

Participants

Reaction Conditions

Reaction Steps

Into a four-neck flask was weighed 15.00 g (24.0 mmol) of the bis(3,5-di-t-butyl-4-methoxyphenyl)(2-bromophenyl)phosphine (7). The atmosphere of the reaction vessel which was fitted with a thermometer, a condenser tube, and a dropping funnel with a pressure-equalizing tube was completely replaced with nitrogen, and 150 mL of anhydrous tetrahydrofuran (hereinafter referred to as THF) was added thereto. Thereto was added dropwise 16.2 mL (25.2 mmol) of n-butyllithium-hexane (1.6 M) solution at −78° C. over a period of 30 minutes, followed by 1 hour of stirring at the same temperature. The resulting mixed solution was cooled to −78° C. and thereto was added dropwise a 10 mL THF solution of 4.15 g (25.2 mmol) of diethyl chlorophosphonite (manufactured by Aldrich) over a period of 30 minutes. After the dropwise addition, a cooling bath was removed and the whole was further stirred at room temperature for 15 hours. After the completion of the reaction, THF was removed by evaporation, the residue was dissolved in 50 mL of diethyl ether, and insoluble matter was removed by filtration. The solvent was removed by evaporation and the residue was purified by active alumina column chromatography (eluent: hexane/ethyl acetate 4/1) to obtain the title compound (14.03 g, a pale yellow solid) Yield 91.5%.

Provenance & Evidence