Hydrochloric Acid → 4H,5H,6H-pyrrolo[1,2-b]pyrazole-2-carboxylic acid

HRID 407828Notes

Reaction equation

HRID 407828 reaction equation
[N:1]1[N:2]2[CH2:13][CH2:12][CH2:11][C:3]2=[CH:4][C:5]=1[C:6]([O:8]CC)=[O:7].[OH-].[Na+].Cl>O1CCOCC1>[N:1]1[N:2]2[CH2:13][CH2:12][CH2:11][C:3]2=[CH:4][C:5]=1[C:6]([OH:8])=[O:7]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 12841166ethyl 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole-2-carboxylate

Product 1

HCID 113670964H,5H,6H-pyrrolo[1,2-b]pyrazole-2-carboxylic acidYield 57%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
65 °C

Procedure

A 25-mL round-bottomed flask equipped with a reflux condenser was charged with ethyl 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole-2-carboxylate (540 mg, 3.0 mmol), 2N Aqueous sodium hydroxide solution (3.5 mL), and 1,4-dioxane (3.0 mL). The system was heated at 65° C. for 2.5 h. It was then cooled to room temperature and adjusted the pH to 2-3 with concentrated HCl. The solid was collected by filtration to afford 162a (260 mg, 57%) as a yellow solid. MS-ESI: [M+H]+ 153.3

Workup

  1. customA 25-mL round-bottomed flask equipped with a reflux condenser
  2. temperatureIt was then cooled to room temperature
  3. filtrationThe solid was collected by filtration

Sources & evidence

ORD record
ord-7d3c9d9cb588420bacdd0a18c74063f8
Source dataset
uspto-grants-2014_06
Patent number
US08754077B2

Reaction notes

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