Acetonyltriphenylphosphonium chloride → 7-chloro-4,5-dihydro-3-[(E)-3-oxo-1-butenyl]-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one

HRID 1606998Notes

Reaction equation

HRID 1606998 reaction equation
[Cl-].[CH2:2]([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[C:3]([CH3:5])=[O:4].[Cl:25][C:26]1[C:31]2[C:32](=[O:43])[N:33]([CH3:42])[CH2:34][C:35]3[N:36]([CH:37]=[N:38][C:39]=3[CH:40]=O)[C:30]=2[CH:29]=[CH:28][CH:27]=1>O1CCCC1>[Cl:25][C:26]1[C:31]2[C:32](=[O:43])[N:33]([CH3:42])[CH2:34][C:35]3[N:36]([CH:37]=[N:38][C:39]=3/[CH:40]=[CH:2]/[C:3](=[O:4])[CH3:5])[C:30]=2[CH:29]=[CH:28][CH:27]=1

Participants

4

Reactant 2

HCID 196994Acetonyltriphenylphosphonium chlorideHCID 198515847-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde

Product 1

HCID 198515567-chloro-4,5-dihydro-3-[(E)-3-oxo-1-butenyl]-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

10.3 g (29 mmol) of acetonyltriphenylphosphonium chloride are suspended in 100 ml of tetrahydrofuran under argon. 3.3 g (29.4 mmol) of potassium tert.-butylate was added thereto and the mixture was thereafter stirred at room temperature for a further 30 minutes. After cooling to 10° 4.0 g (14.5 mmol) of 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde was added thereto and the mixture was stirred at 20° for 1 hour and under reflux for 6 hours. The reaction mixture was evaporated, the residue was partitioned between methylene chloride and water, the organic phase was washed with water and subsequently dried over magnesium sulphate, filtered and evaporated. After chromatography of the residue on silica gel with methylene chloride/ethyl acetate (8:2, 7:3 and 1:1) and subsequent recrystallization of the combined pure fractions from ethyl acetate/hexane there was obtained 7-chloro-4,5-dihydro-3-[(E)-3-oxo-1-butenyl]-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one as white crystals of melting point 235°-237°.

Workup

  1. additionwas added
  2. stirringthe mixture was stirred at 20° for 1 hour
  3. temperatureunder reflux for 6 hours
  4. customThe reaction mixture was evaporated
  5. customthe residue was partitioned between methylene chloride and water
  6. washthe organic phase was washed with water
  7. dry with materialsubsequently dried over magnesium sulphate
  8. filtrationfiltered
  9. customevaporated
  10. customAfter chromatography of the residue on silica gel with methylene chloride/ethyl acetate (8:2, 7:3 and 1:1) and subsequent recrystallization of the combined pure fractions from ethyl acetate/hexane there

Sources & evidence

ORD record
ord-ddcfe2412842491d867badbe3b3e131d
Source dataset
uspto-grants-1989_09
Patent number
US04863920

Reaction notes

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