反应详情

1.35 g (5.0 mmol) of the product from Example 3 was dissolved in 40 ml of methylene chloride and 1 ml of pyridine added. To this solution was added 1.20 g (5.4 mmol) of 4-methoxy-3-methyl benzenesulfonyl chloride. The solution was stirred at room temperature for 6 hours, after which it was concentrated, then diluted with 5 ml of 2N HCl. The residue was extracted 2 times with ethyl acetate, dried (MgSO4) and concentrated. The crude solid so obtained was chromatographed on silica gel, eluting with 20% ethyl acetate:hexane to afford a light yellow solid, which can be recrystallized from ethyl acetate:hexane to yield 1.52 g (72%) of product.

1. concentrationafter which it was concentrated
2. additiondiluted with 5 ml of 2N HCl
3. extractionThe residue was extracted 2 times with ethyl acetate
4. dry with materialdried (MgSO4)
5. concentrationconcentrated
6. customThe crude solid so obtained
7. customwas chromatographed on silica gel
8. washeluting with 20% ethyl acetate
9. customhexane to afford a light yellow solid, which
10. customcan be recrystallized from ethyl acetate