Ethanol → 1-[5-bromo-2-(2-hydroxyethyl)-4-nitro-2H-pyrazol-3-yl]pyrrolidin-3-ol

HRID 9759

Reaction equation

HRID 9759 reaction equation
[Br:1][C:2]1[C:6]([N+:7]([O-:9])=[O:8])=[C:5](Br)[N:4]([CH2:11][CH2:12][OH:13])[N:3]=1.[N:14]1(O)[CH2:18][CH2:17][CH2:16][CH2:15]1.CC[OH:22]>>[Br:1][C:2]1[C:6]([N+:7]([O-:9])=[O:8])=[C:5]([N:14]2[CH2:18][CH2:17][CH:16]([OH:22])[CH2:15]2)[N:4]([CH2:11][CH2:12][OH:13])[N:3]=1

Participants

4

Reactant 3

HCID 702EthanolHCID 800051-HydroxypyrrolidineHCID 130072363,5-Dibromo-1-(2'-hydroxyethyl)-4-nitropyrazole

Product 1

HCID 130072371-[5-bromo-2-(2-hydroxyethyl)-4-nitro-2H-pyrazol-3-yl]pyrrolidin-3-ol

Conditions

Temperature
60 °C

Procedure

A mixture of 2-(3,5-dibromo-4-nitropyrazol-1-yl)ethanol (3) (6.5 g, 21 mmol) and pyrrolidinol (3.75 g, 42 mmol) in EtOH (130 ml) was heated at 60° C. for 15 hours. The reaction was stopped after 67% conversion (monitoring by TLC and HPLC) by evaporating off the solvent under reduced pressure at 40° C. (rotary evaporator). The liquid obtained was purified by column chromatography (gradient of from 5%/95% EtOAc/hexane to 20%/80% EtOAc/hexane). The yellow solid obtained (3.9 g) was recrystallized from EtOH to give 1-[5-bromo-2-(2-hydroxyethyl)-4-nitro-2H-pyrazol-3-yl]pyrrolidin-3-ol (4) in the form of a yellow solid (3.5 g, 53%).

Workup

  1. customby evaporating off the solvent under reduced pressure at 40° C.
  2. custom(rotary evaporator)
  3. customThe liquid obtained
  4. customwas purified by column chromatography (gradient of from 5%/95% EtOAc/hexane to 20%/80% EtOAc/hexane)
  5. customThe yellow solid obtained (3.9 g)
  6. customwas recrystallized from EtOH

Sources & evidence

ORD record
ord-d5a8e2f1fbce433a88bae095a983d4fd
Source dataset
uspto-grants-2006_08
Patent number
US07091350B2

Linked notes

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