反应详情

To a -75° C. (CO2 /isopropanol bath) mixture of lithium bis(trimethylsilyl)amide and tetrahydrofuran (102 mL) under nitrogen was added a 0° C. solution consisting of 3-(4-bromobutyl)-4-thiazolidinone (11.65 g), iodomethane (20.8 g) and tetrahydrofuran (20 mL) over a period of 20 min. The resultant solution was stirred at -75° C. for 25 min. TLC analysis (silica gel, 32% EtOAc/hexane) of a small aliquot acidified with 1N HCl showed the absence of a starting bromide and the presence of a major product, Rf ≅0.41. The reaction mixture was removed from the cold bath and acidified with 1N HCl (200 mL). The aqueous mixture was extracted with diethyl ether (3×175 mL). The combined extracts were washed with brine (200 ml), dried over Na2SO4 and concentrated in vacuo to an oil. The crude oil was chromatographed (Waters Prep 500, 2 silica gel columns, 30% EtOAc/hexane) to give 11.02 g of an oil as the major product, Rf ≅0.41. A sample (2.80 g) of this was distilled using a short path head yielding 2.68 g of a faint yellow oil (bath temperature 90°-100° C./0.05 mm Hg).

1. additionwas added a 0° C. solution
2. customThe reaction mixture was removed from the cold bath
3. extractionThe aqueous mixture was extracted with diethyl ether (3×175 mL)
4. washThe combined extracts were washed with brine (200 ml)
5. dry with materialdried over Na2SO4
6. concentrationconcentrated in vacuo to an oil
7. customThe crude oil was chromatographed (Waters Prep 500, 2 silica gel columns, 30% EtOAc/hexane)