N-bromobutanimide → 3-bromo-2-(4-fluorophenyl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole

HRID 628462Notes

Reaction equation

HRID 628462 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[C:10]3[CH2:15][CH2:14][CH2:13][N:11]3[N:12]=2)=[CH:4][CH:3]=1.[Br:16]N1C(=O)CCC1=O>C(Cl)(Cl)Cl.O>[Br:16][C:9]1[C:8]([C:5]2[CH:4]=[CH:3][C:2]([F:1])=[CH:7][CH:6]=2)=[N:12][N:11]2[CH2:13][CH2:14][CH2:15][C:10]=12

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 674372812-(4-fluorophenyl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole

Product 1

HCID 894883353-bromo-2-(4-fluorophenyl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent

Procedure

To a solution of 2-(4-fluorophenyl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole (44.5 g, 0.22 mol) in 600 mL chloroform is added at 0° C. N-bromosuccinimide (117 g, 0.66 mol). The mixture is stirred 17 h at RT. Thereafter, the mixture is diluted with water and extracted with dichloromethane. The combined organic phases are dried and evaporated. The obtained crude material is purified by column chromatography on silica (6 cm×40 cm, eluent dichloromethane). The obtained product is further purified by trituration with a MTBE-hexane mixture and 38.2 g (61%) of the product are obtained as solid.

Workup

  1. extractionextracted with dichloromethane
  2. customThe combined organic phases are dried
  3. customevaporated
  4. customThe obtained crude material
  5. customis purified by column chromatography on silica (6 cm×40 cm, eluent dichloromethane)
  6. customThe obtained product is further purified by trituration with a MTBE-hexane mixture and 38.2 g (61%) of the product
  7. customare obtained as solid

Sources & evidence

ORD record
ord-974719f3707449e8bffa090a1bb6cd95
Source dataset
uspto-grants-2016_04
Patent number
US09314026B2

Reaction notes

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