反应详情

To a solution of (−)-6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone (20 g) and dilute hydrochloric acid (52 ml of concentrated hydrochloric acid in 789 ml of water), 8 g of dilute sodium nitrite (8 g of sodium nitrite in 52 ml of water) was added and stirred. After 10 minutes, malononitrile solution (6.3 g malononitrile in 52 ml of water) was added. The solution was stirred for 1 hour at room temperature. The pH of the suspension was adjusted to 6.0 with sodium acetate solution. The suspension was filtered, washed with water followed by ethanol and then dried to obtain solid levosimendan (yield—22 g, purity—99.9%).

1. stirringThe solution was stirred for 1 hour at room temperature
2. filtrationThe suspension was filtered
3. washwashed with water
4. customdried