was recooled to 55 u00b0 more dry pyrrolidine 3 24 ml and n butyllithium 2 5m in hexane 13 92 ml were added and the mixture was warmed up to 25 u00b0 after 2 5 hours iodomethane 1 56 ml was added and the mixture was stirred for another hour the resulting mixture was quenched with 10 potassium bisulfate solution 100 ml at 25 u00b0 warmed up to room temperature saturated with sodium chloride and extracted with ethyl acetate 3 u00d7 100 ml the combined ethyl acetate extracts were washed with a small amount of 5 sodium bicarbonate and brine dried over anhydrous sodium sulfate and evaporated in vacuo to give a gummy residue 11 0 g the above gum was refluxed in dry toluene 200 ml under an atmosphere of nitrogen for 4 0 hours the solvent was then evaporated in vacuo to give a gummy material this gum was chromatographed on a column of silica gel lps 1 450 g eluting with ethyl acetate hexane 1 3 to give 7 3 g 67 5 of compound c as a gum with consistent 1 h nmr and 13 c nmr spectra to a chilled 0 u00b0 ice bath and stirred solution of compound c 7 3 g 13 52 mmol in dry dichloromethane 80 ml under an atmosphere of nitrogen was added dry n n dimethylaniline 3 7 g 30 53 mmol after 15 minutes benzyl bromomethyl ether 5 62 g 26 13 mmol was added the resulting solution was gradually warmed up to room temperature and stirred.