反应详情

A solution of 0.44 ml (6.2 mmol) of dimethylsulfoxide in 25 ml of dichloromethane was cooled under inert atmosphere to -63° C., treated with 2.3 ml (4.6 mmol) of oxalyl chloride (2M in dichloromethane), and stirred for 15 min. A solution of 0.75 g (3.1 mmol) of the resultant compound of Example 4 in 10 ml of dichloromethane was subsequently added, the solution was stirred for 30 min, and 173 ml (12.4 mmol) of triethylamine was added. After stirring for an additional 15 min, the solution was quenched with 10% aqueous citric acid, poured into a mixture of 1:1 ether:hexane and 10% citric acid, extracted with ether, washed with aqueous brine, dried over MgSO4, and concentrated to a yellow oil. Purification by flash chromatography using 20% ethyl acetate in hexane gave 0.62 g (83%) of the desired compound as a white, crystalline solid, m.p. 55°-57° C. 1H NMR (CDCl3) δ 4.89 (s, 4H), 6.92 (m, 4H), 7.02 (m, 2H), 7.30 (m, 4H). Mass spectrum (M+NH4)+= 260.

1. stirringthe solution was stirred for 30 min
2. stirringAfter stirring for an additional 15 min
3. customthe solution was quenched with 10% aqueous citric acid
4. additionpoured into a mixture of 1:1 ether
5. extractionhexane and 10% citric acid, extracted with ether
6. washwashed with aqueous brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated to a yellow oil
9. customPurification by flash chromatography