Reaction #2298615

Reaction equation

7-methyl-3H-thieno[3,2-d]pyrimid-4-one

7-Methyl-3H-thieno[3,2-d]pyrimid-4-one

phosphorus oxychloride

sodium bicarbonate

→

4-chloro-7-methylthieno[3,2-d]pyrimidine

Yield 96.0%

Conditions

Workup

1. 1
   Temperatureat reflux for 1 hour
2. 2
   ExtractionThe aqueous mixture was extracted with diethyl ether
3. 3
   WashThe organic layer was washed with water
4. 4
   Dryingdried over anhydrous magnesium sulfate
5. 5
   Otherthe solvent evaporated under reduced pressure

Procedure

A solution of 7-methyl-3H-thieno[3,2-d]pyrimid-4-one (3, 2.9 g, 18 mmol) in phosphorus oxychloride (18 mL) under N2 was heated at reflux for 1 hour. The resulting solution as allowed to cool to room temperature and then poured into a saturated aqueous solution of sodium bicarbonate to neutralize. The aqueous mixture was extracted with diethyl ether. The organic layer was washed with water followed by saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate and the solvent evaporated under reduced pressure to yield 4-chloro-7-methylthieno[3,2-d]pyrimidine (3.1 g, 96% yield) as a white solid.

Source