Reaction #83239

Reaction equation

4,7-dihydro-6-ethoxycarbonyl-2-(4-fluorophenyl)-3-(pyridin-4-yl)-7-oxopyrazolo[1,5-a]pyrimidine

lithium borohydride

→

6-ethoxycarbonyl-2-(4-fluorophenyl)-7-oxo-3-(pyridin-4-yl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine

Yield 39.8%

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   Temperaturethe mixture was refluxed for 1 hour
2. 2
   TemperatureAfter cooling
3. 3
   Otherthe reaction mixture was quenched with an aqueous saturated ammonium chloride solution
4. 4
   Extractionextracted with ethyl acetate
5. 5
   WashThe extracts were washed with brine
6. 6
   Otherdried
7. 7
   Concentrationconcentrated in vacuo
8. 8
   OtherThe residue was crystallized from ethanol

Procedure

To a mixture of 4,7-dihydro-6-ethoxycarbonyl-2-(4-fluorophenyl)-3-(pyridin-4-yl)-7-oxopyrazolo[1,5-a]pyrimidine (100 mg) in tetrahydrofuran (4 ml) was added lithium borohydride (2 mole in tetrahydrofuran, 0.26 ml) at room temperature and the mixture was refluxed for 1 hour. After cooling, the reaction mixture was quenched with an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The extracts were washed with brine, dried and concentrated in vacuo. The residue was crystallized from ethanol to give 6-ethoxycarbonyl-2-(4-fluorophenyl)-7-oxo-3-(pyridin-4-yl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine (40 mg).

Source