N-bromobutanimide → 8-bromo-10a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one

HRID 1910922Notes

Reaction equation

HRID 1910922 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]23[NH:20][CH2:19][CH2:18][N:9]2[C:10](=[O:17])[C:11]2[N:12]([CH:14]=[CH:15][CH:16]=2)[CH2:13]3)=[CH:4][CH:3]=1.[Br:21]N1C(=O)CCC1=O>C1COCC1>[Br:21][C:15]1[CH:16]=[C:11]2[C:10](=[O:17])[N:9]3[CH2:18][CH2:19][NH:20][C:8]3([C:5]3[CH:6]=[CH:7][C:2]([Cl:1])=[CH:3][CH:4]=3)[CH2:13][N:12]2[CH:14]=1.[Br:21][C:14]1[N:12]2[CH2:13][C:8]3([C:5]4[CH:6]=[CH:7][C:2]([Cl:1])=[CH:3][CH:4]=4)[NH:20][CH2:19][CH2:18][N:9]3[C:10](=[O:17])[C:11]2=[CH:16][CH:15]=1

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 6736965310a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one

Product 2

HCID 584063618-bromo-10a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-oneHCID 584063827-bromo-10a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 10a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one (100 mg, 0.35 mmol) dissolved in THF (20 mL) was added N-bromosuccinimide (62 mg, 0.35 mmol) and the reaction mixture was stirred at room temperature for 1 h. LCMS analysis showed a mixture of mono brominated product (366/368 m/z), a small amount of dibrominated pyrrole (446 m/z) and debrominated starting material (288 m/z). The reaction mixture was partitioned with water (25 ml) and CH2CL2 (25 mL) and the organic layer was separated and concentrated in vacuo to give crude product (light yellow oil). The crude mixture was then purified using flash chromatography (Biotage SP4, 12 g cartridge, 0-10% MeOH gradient in CH2Cl2) to give 7-bromo-10a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one (A) and 8-bromo-10a-(4-chlorophenyl)-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one (B) in a 0.6:1 ratio (98.4 mg, yield 77%).

Workup

  1. additiona mixture
  2. customThe reaction mixture was partitioned with water (25 ml) and CH2CL2 (25 mL)
  3. customthe organic layer was separated
  4. concentrationconcentrated in vacuo
  5. customto give crude product (light yellow oil)
  6. customThe crude mixture was then purified

Sources & evidence

ORD record
ord-a99f9d63a650445abb40019d8ba95cef
Source dataset
uspto-grants-2013_12
Patent number
US08604034B2

Reaction notes

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