Iodine → HCID 18991841, compound

Participants

Reaction Conditions

Reaction Steps

dc) 16.8 g (50 mmol) of (3-methoxyphenyl)-di-p-tolylphosphine oxide were dissolved in 100 ml of dry THF in a 1 l four-necked sulphonation flask provided with a stirrer, dropping funnel, thermometer and argon gasification. In a separate Schlenk tube 34.0 ml of 1.6N n-butyllithium solution in hexane (54.4 mmol) were added dropwise under argon and while stirring at -78° C. to a solution of 9.98 g (70.6 mmol) of 2,2,6,6-tetramethylpiperidine in 50 ml of THF. The solution was warmed to 0° C. for a short period, then again cooled to -78° C. and then added dropwise via a canula at ≤-70° C. to the solution of the phosphine oxide in THF. The resulting red-brown solution was stirred at -78° C. for a further 30 minutes and then treated dropwise with a solution of 15.0 g (59.1 mmol) of iodine in 50 ml of THF, whereby a beige precipitate formed. The reaction mixture was left to warm to 0° C., treated with aqueous sodium pyrosulphite solution and extracted with ethyl acetate. The extracts were washed with sat. NaHCO3 solution and sat. NaCl solution, dried over Na2SO4, filtered and evaporated. The residue was chromatographed on silica gel (200 g, ethyl acetate), whereby 15.3 g of (2-iodo-3-methoxyphenyl)-di-p-tolylphosphine oxide were obtained. After recrystallization from t-butyl methyl ether there was obtained a white powder with a m.p. of 146°-148° C.

Provenance & Evidence