Potassium Hydroxide → 3-bromo-2-methyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole

HRID 1909058Notes

Reaction equation

HRID 1909058 reaction equation
[Br:1][C:2]1[C:3]([CH3:11])=[N:4][NH:5][C:6]=1[CH2:7][CH2:8][CH2:9]Cl.[OH-].[K+]>C(O)(C)C.O>[Br:1][C:2]1[C:3]([CH3:11])=[N:4][N:5]2[CH2:9][CH2:8][CH2:7][C:6]=12

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 178434607HCID 178434607, compound

Product 1

HCID 665994623-bromo-2-methyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoleYield 49%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3776IsopropanolSolvent

Procedure

To a solution of 4-bromo-5-(3-chloro-propyl)-3-methyl-1H-pyrazole (2.42 g, 10.2 mmol) in isopropyl alcohol (35 mL) was added KOH (0.86 g, 15.3 mmol) dissolved in water (7 mL). The reaction was heated to reflux for 4 h. After cooling the reaction was partially concentrated, diluted with EtOAc and washed with brine. The organic layer was dried over Na2SO4, filtered and concentrated to give a light yellow oil as the desired product (1.01 g, 5.0 mmol). MS m/z 203.4 (M+H)+.

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux for 4 h
  3. temperatureAfter cooling the reaction
  4. concentrationwas partially concentrated
  5. additiondiluted with EtOAc
  6. washwashed with brine
  7. dry with materialThe organic layer was dried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-afe1c77df44c433591b865d1cdc7202e
Source dataset
uspto-grants-2013_12
Patent number
US08598217B2

Reaction notes

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