| 摘要 |
PURPOSE:The reaction between a salicyl aldehyde derivative and malononitrile is conducted in the presence of a base first, and then of an acid to produce the titled compound used as an intermediate of an allergic agent through simple operations in the same reaction system in a short time in high yield. CONSTITUTION:The reaction between a salicyl aldehyde derivative of formula I (R1, R2, R3 and R4 are the same or different H, halogen, alkyl, alkenyl, alkoxy, alkenyloxy, hydroxyl, the two adjacent substituents among R1, R2, R3, and R4 may form a condensed carbon ring together with the carbon atoms adjacent to them where 2,3-dihydroxybenzaldehyde is excluded) such as salicyl aldehyde and malononitrile is conducted in the same reaction system in the presence of a base such as lithium or methylamine and then of an acid such as hydrochloric acid, preferably in a solvent such as methanol at 20-80 deg.C to give a compound of formula II (3-cyano-8- hydroxycoumarin is excluded). |
