Reaction #45869

Reaction equation

Dess-Martin reagent

2-Cyclopropyl-7-[(1S*,3R*)-3-hydroxycyclopentyl]-5-methyl-6-phenyl-1,3-benzoxazole-4-carbonitrile

sodium thiosulfate

sodium hydrogencarbonate

→

compound

Yield 89.0%

2-Cyclopropyl-5-methyl-7-(3-oxocyclopentyl)-6-phenyl-1,3-benzoxazole-4-carbonitrile

Yield 89.0%

Solvents

dichloromethane

Conditions

Workup

1. 1
   Temperatureagain cooled at 0° C.
2. 2
   workup.STIRRINGby further stirring for 10 minutes
3. 3
   ExtractionThe solution was extracted three times with dichloromethane
4. 4
   Washwashed with saturated brine
5. 5
   Dryingdried over anhydrous sodium sulfate
6. 6
   OtherThe insoluble matter was separated by filtration
7. 7
   Otherthe solvent was evaporated away
8. 8
   Otherthe resulting residue was purified by middle-pressure liquid chromatography (eluent, n-hexane

Procedure

2-Cyclopropyl-7-[(1S*,3R*)-3-hydroxycyclopentyl]-5-methyl-6-phenyl-1,3-benzoxazole-4-carbonitrile (I-302) (50 mg, 0.14 mmol) was dissolved in dichloromethane (1 ml), and at 0° C., Dess-Martin reagent (118 mg, 0.28 mmol) was added. The solution was stirred at room temperature for 3 hours, then again cooled at 0° C., and aqueous saturated sodium thiosulfate solution and an aqueous saturated sodium hydrogencarbonate solution were added, followed by further stirring for 10 minutes. The solution was extracted three times with dichloromethane. The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The insoluble matter was separated by filtration, the solvent was evaporated away and the resulting residue was purified by middle-pressure liquid chromatography (eluent, n-hexane:ethyl acetate=3:1, v/v) to obtain the entitled compound (44 mg, 89%) as a white solid.

Source