反应详情

To a -20° C. solution, under argon, of 8.4 ml of trifluoromethanesulfonic anhydride in 75 ml of methylene chloride is added, dropwise, a solution of 5.9 g of product from Example 268 and 4.05 ml of pyridine in 25 ml of methylene chloride. The temperature is maintained below -10° C. during the addition. The progress of the reaction is monitored by tic. The reaction is filtered and the filtrate concentrated in vacuo to an oily residue, The residue is purified by chromatography (silica gel: 50% ethyl acetate/hexane) to give 7.03 g of the desired product.

1. temperatureThe temperature is maintained below -10° C. during the addition
2. filtrationThe reaction is filtered
3. concentrationthe filtrate concentrated in vacuo to an oily residue
4. customThe residue is purified by chromatography (silica gel: 50% ethyl acetate/hexane)