Benzamide → N-Benzoyl-tetrahydro-3-oxo-1,1-diphenyl-3H-oxazolo[3,4-a]pyrazine-7(1H)-carboxamide

HRID 1713531Notes

Reaction equation

HRID 1713531 reaction equation
[C:1]([NH2:9])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(Cl)(=O)[C:11](Cl)=[O:12].[C:16]1([C:22]2([C:32]3[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=3)[CH:26]3[CH2:27][NH:28][CH2:29][CH2:30][N:25]3[C:24](=[O:31])[O:23]2)[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>ClCCCl>[C:1]([NH:9][C:11]([N:28]1[CH2:29][CH2:30][N:25]2[C:24](=[O:31])[O:23][C:22]([C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)([C:32]3[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=3)[CH:26]2[CH2:27]1)=[O:12])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 2331BenzamideHCID 65578Oxalyl chlorideHCID 231218811,1-Diphenyltetrahydro-1H-oxazolo[3,4-a]pyrazin-3(5H)-one

Product 1

HCID 23121963N-Benzoyl-tetrahydro-3-oxo-1,1-diphenyl-3H-oxazolo[3,4-a]pyrazine-7(1H)-carboxamideYield 23.3%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
90 °C

Procedure

Benzamide (1.0 g, 8.3 mmol) was dissolved in 1,2-dichloroethane (5 mL), oxalyl dichloride (1.2 g, 9.1 mmol) was added thereto, and the mixture was stirred at 90° C. for 30 hours. The reaction solution was concentrated under reduced pressure. Toluene (4 mL) was added thereto and dissolved. Hexahydro-1,1-diphenyl-3H-oxazolo[3,4-a]pyrazin-3-one (0.20 g, 0.68 mmol) was added thereto, and the mixture was stirred at 60° C. for 6 hours. The reaction solution was concentrated under reduced pressure to a half its original volume, and the precipitated crystals were filtered off. The residue was purified with silica gel column chromatography (hexane:ethyl acetate=1:1), and toluene (4 mL) was added thereto. The precipitated crystals were filtered off, and the filtrate was concentrated. The residue was further purified with silica gel column chromatography (hexane:ethyl acetate=1:1) and crystallized from diisopropyl ether to obtain the title compound (70 mg, yield 23%).

Workup

  1. concentrationThe reaction solution was concentrated under reduced pressure
  2. additionToluene (4 mL) was added
  3. dissolutiondissolved
  4. stirringthe mixture was stirred at 60° C. for 6 hours
  5. concentrationThe reaction solution was concentrated under reduced pressure to a half its original volume
  6. filtrationthe precipitated crystals were filtered off
  7. customThe residue was purified with silica gel column chromatography (hexane:ethyl acetate=1:1), and toluene (4 mL)
  8. additionwas added
  9. filtrationThe precipitated crystals were filtered off
  10. concentrationthe filtrate was concentrated
  11. customThe residue was further purified with silica gel column chromatography (hexane:ethyl acetate=1:1)
  12. customcrystallized from diisopropyl ether

Sources & evidence

ORD record
ord-b16e9979b6494ab2a04385d37305622a
Source dataset
uspto-grants-2010_09
Patent number
US07795267B2

Reaction notes

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