Pyridine → 6-(4-Benzyl-1-piperazinylcarbonyl)-3,4-dihydrocarbostyril

1.9 Grams of 6-carboxy-3,4-dihydrocarbostyril was suspended in 200 ml of methylene chloride, then 2 ml of pyridine was added to the suspension and under stirring 1.4 g of thionyl chloride was added dropwise in keeping the inside temperature at 0°-20° C. After the addition of thionyl chloride, the reaction mixture was kept at the same temperature and stirred for 1 hour, then 1.74 g of benzylpiperazine in 10 ml of methylene chloride solution was added to the mixture. Then the reaction mixture was further stirred at a room temperature for 4 hours. The reaction mixture was washed thoroughly with an aqueous solution of potassium carbonate, then washed with water and a diluted hydrochloric acid, dried with anhydrous sodium sulfate and the solvent was removed by distillation. The residue thus obtained was treated by a silica gel column chromatography (Silica gel: Wako C-200, eluate:chloroform:methanol (volume/volume)=20:1). The objective product was recrystallized from ethanol to obtain 325 mg of 6-(4-benzyl-1-piperazinylcarbonyl)-3,4-dihydrocarbostyril. Colorless needle-like crystals. Melting point: 198°-200° C.

1. additionwas added dropwise
2. customat 0°-20° C
3. stirringThen the reaction mixture was further stirred at a room temperature for 4 hours
4. washThe reaction mixture was washed thoroughly with an aqueous solution of potassium carbonate
5. washwashed with water
6. dry with materiala diluted hydrochloric acid, dried with anhydrous sodium sulfate
7. customthe solvent was removed by distillation
8. customThe residue thus obtained
9. customThe objective product was recrystallized from ethanol

ORD-Eintrag

ord-340e3a5c8ddb49469ca5db38d17cb8fe

Quelldatensatz

uspto-grants-1984_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04468402