反应详情

To a solution of 0.14 g of 2-amino-5-[(4-acetyl-3-hydroxy-2-propylbenzyl)thio]-1,3,4-thiadiazole obtained in Example 5 and 0.15 g of mono-p-methoxybenzyl malonate in 3 ml of pyridine were added 0.15 g of dicyclohexylcarbodiimide and a catalytic amount of p-toluenesulfonic acid. The resultant mixture was stirred at room temperature for hours. During the stirring, 0.15 g each of mono-p-methoxybenzyl malonate and dicyclohexylcarbodiimide were supplemented to the system. After completion of the reaction, ethyl acetate was added to the system. After insoluble matters were filtered off, the filtrate was concentrated under reduced pressure The obtained residue was dissolved in chloroform. The solution was washed with, in sequence, 1N hydrochloric acid, water, a saturated aqueous sodium bicarbonate solution and water and then, dried over anhydrous magnesium sulfate The solvent was then removed by distillation. The resultant residue was subjected to silica gel column chromatography followed by elution with a mixture of chloroform-methanol (4:1). The eluate was recrystallized from isopropyl alcohol to give 0.04 g of p-methoxybenzyl 3-[[5-[(4-acetyl-3-hydroxy-2-propylbenzyl)thio]-1,3,4-thiadiazol-2-yl]amino]-3-oxopropionate.

1. additionwas added to the system
2. filtrationAfter insoluble matters were filtered off
3. concentrationthe filtrate was concentrated under reduced pressure The obtained residue
4. dissolutionwas dissolved in chloroform
5. washThe solution was washed with, in sequence, 1N hydrochloric acid, water
6. dry with materiala saturated aqueous sodium bicarbonate solution and water and then, dried over anhydrous magnesium sulfate The solvent
7. customwas then removed by distillation
8. washfollowed by elution with a mixture of chloroform-methanol (4:1)
9. customThe eluate was recrystallized from isopropyl alcohol