反应详情

A solution of 3.42 g (0.01 mol) of α-acetyl-N-(2- -methoxyethyl)-N-methyl-3-nitrostyrenesulfonamide and 1.87 g (0.01 mol) of 3-aminocrotonic acid 2-propoxyethyl ester in 15 ml of isopropanol is heated to reflux for 2 hours, thereupon treated with 1.0 g of Amberlyst® 15 as the catalyst and then heated to reflux for an additional 30 minutes. After concentration under reduced pressure 0 the oily residue is dissolved in methylene chloride, the catalyst remaining behind is removed by filtration under suction, and the filtrate is washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate and concentrated to dryness. The residual oil is chromatographed on 300 g of silica gel with methylene chloride/ethyl acetate (4:1) as the elution agent. The uniform fractions yield an oil which crystallizes upon trituration and leaving to stand under hexane. After recrystallization from ether, there are obtained 2.4 g (47%) of 1,4-dihydro-2 6-dimethyl-5-[(2-methoxyethyl)methylsulfamoyl]-4-(3-nitrophenyl)nicotinic acid 2-propoxyethyl ester. m.p. 67°-70°, as an almost colorless crystalline powder.

1. temperatureto reflux for 2 hours
2. additiontreated with 1.0 g of Amberlyst® 15 as the catalyst
3. temperatureheated
4. temperatureto reflux for an additional 30 minutes
5. concentrationAfter concentration under reduced pressure 0 the oily residue
6. dissolutionis dissolved in methylene chloride
7. customthe catalyst remaining behind is removed by filtration under suction
8. washthe filtrate is washed with a saturated aqueous sodium chloride solution
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated to dryness
11. customThe residual oil is chromatographed on 300 g of silica gel with methylene chloride/ethyl acetate (4:1) as the elution agent
12. customThe uniform fractions yield an oil which
13. customcrystallizes upon trituration
14. customleaving
15. customAfter recrystallization from ether, there