| Molecular Formula | C10H7ClO3 |
| Molar Mass | 210.61378 |
| Physical and Chemical Properties | Chemical properties 3-chloro-4-methyl-7-hydroxycoumarin is a colorless solid, m.p.242 ~ 244 ℃, insoluble in water. |
| Use | Use 3-chloro-4-methyl-7-hydroxycoumarin is an intermediate of muscarinic phosphorus, an organophosphorus pesticide. |
The preparation method is to react resorcinol with ethyl α-chloroacetoacetate to obtain 3-chloro-4-methyl-7-hydroxycoumarin.
Resorcinol was dissolved in an appropriate amount of ethanol, and then α-ethyl chloroacetoacetate (molar ratio of reactants 1 ∶ 1) was added to make a mixed solution. Place an appropriate amount of concentrated sulfuric acid in the reactor, drop the mixed reaction solution into the concentrated sulfuric acid at low temperature and stirring, continue to stir for several hours after addition, and then leave it at room temperature for 24 hours. Under stirring, the reactants are slowly put into ice and water, and solids are precipitated. After standing, the upper layer of water is poured out, the solid is filtered out, and after washing with water, the solid is dissolved with dilute NaOH solution. The insoluble matter is filtered out, the filtrate is acidified with dilute H2SO4, coumarin is precipitated, and the product is obtained after filtration, water washing and drying.