Bromine → 3-bromo-4H,5H,6H-pyrrolo[1,2-b]pyrazole

HRID 595242Notes

Reaction equation

HRID 595242 reaction equation
[Br:1]Br.[N:3]1[N:4]2[CH2:10][CH2:9][CH2:8][C:5]2=[CH:6][CH:7]=1.CC([O-])=O.[Na+].C(=O)(O)[O-].[Na+]>CC(O)=O>[Br:1][C:6]1[CH:7]=[N:3][N:4]2[CH2:10][CH2:9][CH2:8][C:5]=12

Participants

6

Reactant 4

HCID 24408BromineHCID 516892Sodium BicarbonateHCID 517045Sodium AcetateHCID 110733655,6-Dihydro-4H-pyrrolo(1,2-b)pyrazole

Product 1

HCID 152870713-bromo-4H,5H,6H-pyrrolo[1,2-b]pyrazoleYield 90.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Bromine (22.4 mL, 435 mmol) was added to a solution of 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole 8 (47.2 g, 437 mmol) and NaOAc (36.2 g, 440 mmol) in AcOH (750 mL) drop wise at 0° C. The mixture was stirred at the same temperature for 10 minutes then neutralized by the addition of aqueous sodium bicarbonate. The aqueous layer was extracted with EtOAc (5×200 mL) and the organic extracts were dried over magnesium sulfate and concentrated under reduced pressure to afford 3-bromo-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole (73.5 g).

Workup

  1. extractionThe aqueous layer was extracted with EtOAc (5×200 mL)
  2. dry with materialthe organic extracts were dried over magnesium sulfate
  3. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-a1ce133a010f4fa887c1633120629127
Source dataset
uspto-grants-2016_01
Patent number
US09242984B2

Reaction notes

Loading…