1) Synthesis of 3-(4-methoxybenzoyl)propionic acid (3)
100 mL of dichloromethane was added to a 250 mL three-necked flask, and anhydrous aluminum chloride (25.9 g, 1.942 mol)
and anisole (10 g, 0.092 mol) were added in portions under stirring. The temperature was controlled at -5~59°C and the
reaction was kept warm for 4 hours. After the reaction, the reaction solution was transferred to 200 mL of 3 mol/L dilute
hydrochloric acid, and the dichloromethane was evaporated under reduced pressure. The product was precipitated in the aqueous
phase, filtered and dried to obtain 17.2 g of white powder with a purity of 90%. It was recrystallized with 17.2 mL of ethanol
to obtain 15 g of white crystals with a purity of 99%, a yield of 78%, and a melting point of 146.2~146.7.
2) Synthesis of 4-(4-methoxyphenyl)butyric acid (4)
Into a 250mL three-necked flask, add 100mL of diethylene glycol ether, compound 3 (12g, 0.058mol),
80% hydrazine hydrate (7.2g. 0.115mol), potassium hydroxide (13g. 0.Chemicalbook232mol), slowly heat to 150~180°C,
and reflux for 4 hours. After the reaction is completed, transfer to 1L of water, adjust to acidity with
concentrated hydrochloric acid, precipitate the product, filter, rinse with about 50mL of water,
and dry at 45~50°C to obtain 9.9gof white powder with a purity of 99% and a yield of 89%.
3) Synthesis of 7-methoxy-1-tetralone
Add 20g of concentrated sulfuric acid to a 100mL three-necked flask, heat to 50-60°C, add compound 4 (10g, 0.052mol) in portions,
keep warm for 1h after addition, wait for the reaction to be completed, transfer to 350mL of cold water Chemicalbook,
extract with 350mL of toluene x 3, compress the organic phase to dryness, add 50mL of petroleum ether,
stir at room temperature to precipitate,filter, rinse with 20mL of petroleum ether, and dry at 50°C to obtain 7.5g
of light yellow crystals with a purity of 99% and a yield of 82%. |
