Acetone → 8-(2-Propynyloxy)-5-hydroxy-3,4-dihydrocarbostyril

Participants

Reaction Steps

2 liters of acetone and 500 ml of water were added to 150 g of 5,8-dihydroxy-3,4-dihydrocarbostyril, and 138 g of potassium carbonate and 150 g of 2-propynyl bromide were further added thereto. The resulting mixture was heated while refluxing for 3 hours on a water bath. After completion of the reaction, the acetone and the 2-propynyl bromide were evaporated under reduced pressure, and the residue was made acidic with concentrated hydrochloric acid. The mixture was extracted with chloroform, and the chloroform layer was washed with water and dried over anhydrous sodium sulfate. The chloroform was evaporated under reduced pressure, and the residual crystals were recrystallized from isopropanol-diethyl ether to obtain 110 g of 8-(2-propynyloxy)-5-hydroxy-3,4-dihydrocarbostyril having a melting point of 141°-142° C.

Provenance & Evidence