Reaction #2389076

Reaction equation

sodium methoxide

2-acetyl-5-bromo-6-methoxynaphthalene

ethyl acetate

sodium methoxide

hydrochloric acid

sodium methoxide

→

product

4-(5-Bromo-6-methoxy-2-naphthyl)-4-hydroxybut-3-en-2-one

Conditions

Workup

1. 1
   Otherequipped with refrigerator and stirrer
2. 2
   workup.ADDITIONare added
3. 3
   Othergoes up to 55° C.
4. 4
   Otherat 65° C.
5. 5
   TemperatureThe reaction mixture is then heated
6. 6
   Temperatureto reflux for 15 minutes
7. 7
   Temperaturecooled to 5° C. in one hour
8. 8
   workup.WAITkept at this temperature for 2 hours
9. 9
   FiltrationThe precipitated solid is filtered
10. 10
    Washabundantly washed with water on the filter
11. 11
    Washwashed with ethyl acetate
12. 12
    Otherdried in oven under vacuum

Procedure

139.4 Grams (0.499 moles) of 2-acetyl-5-bromo-6-methoxynaphthalene and 1450 ml of ethyl acetate are placed in a flask equipped with refrigerator and stirrer and, under stirring and at the temperature of 45° C., 30 g (0.556 moles) of sodium methoxide are added. The temperature of the reaction mixture goes up to 55° C. and is kept at 65° C. for one hour, then other 10 g (0.185 moles) of sodium methoxide are added and, after half an hour, still other 10 g (0.185 moles) of sodium methoxide, always under stirring and keeping the temperature at 65° C. for another hour and half. The reaction mixture is then cooled to room temperature and brought to pH 4 by adding a concentrated aqueous solution of hydrochloric acid. The reaction mixture is then heated to reflux for 15 minutes, cooled to 5° C. in one hour and kept at this temperature for 2 hours. The precipitated solid is filtered, abundantly washed with water on the filter, then washed with ethyl acetate and dried in oven under vacuum obtaining 145.7 g of product with a yield equal to 90.8%.

Source