Reaction #3758

Reaction equation

trans-2-phenylcyclopentanecarboxylic acid (3,5-diallyl-2-amino-4,6-dioxo-cyclohex-1-enyl)amide

potassium hydroxide

→

5,7-diallyl-2-(2-phenylcyclopentyl)-1,7-dihydrobenzoimidazole-4,6-dione

Yield 52.4%

Solvents

water

ethanol

Conditions

Workup

1. 1
   Temperatureheat
2. 2
   Otherthe reaction to 60° C. for 4 hours
3. 3
   TemperatureCool
4. 4
   Otherthe reaction
5. 5
   ExtractionAcidify with concentrated hydrochloric acid and extract with diethyl ether (400 ml)
6. 6
   WashRinse the
7. 7
   Extractionorganic extract with water (200 ml), saturated sodium chloride (200 ml)
8. 8
   Dryingdry over anhydrous magnesium sulfate
9. 9
   Filtrationfilter
10. 10
    Concentrationconcentrate under vacuum
11. 11
    OtherPurify the residue by radial chromatography (40% to 50% ethyl acetate/hexane, 2 mm plate)

Procedure

Dissolve trans-2-phenylcyclopentanecarboxylic acid (3,5-diallyl-2-amino-4,6-dioxo-cyclohex-1-enyl)amide (300 mg, 0.76 mmol) in ethanol (100 ml), add 10% potassium hydroxide (100 ml) and heat the reaction to 60° C. for 4 hours. Cool the reaction and dilute with water (200 ml). Acidify with concentrated hydrochloric acid and extract with diethyl ether (400 ml). Rinse the organic extract with water (200 ml), saturated sodium chloride (200 ml), dry over anhydrous magnesium sulfate, filter and concentrate under vacuum. Purify the residue by radial chromatography (40% to 50% ethyl acetate/hexane, 2 mm plate) to provide 5,7-diallyl-2-(2-phenylcyclopentyl)-1,7-dihydrobenzoimidazole-4,6-dione (149 mg).

Source