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 1753145Notes

Reaction equation

HRID 1753145 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%). The mixture was used without further purification in the next step.

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-822e8c676e3a4eb0871f20c76bbdc578
Source dataset
uspto-grants-2015_10
Patent number
US09163029B2

Reaction notes

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