Tetrahydrofuran → 5-(2-Bromoacetyl)pyrazole-3-carboxylic acid ethyl ester

HRID 129832Notes

Reaction equation

HRID 129832 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[C:9]([C:11](=[O:13])[CH3:12])[NH:8][N:7]=1)=[O:5])[CH3:2].O1CCCC1.[Br-:19].[Br-].[Br-].C1([N+](C)(C)C)C=CC=CC=1.C1([N+](C)(C)C)C=CC=CC=1.C1([N+](C)(C)C)C=CC=CC=1>O>[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[C:9]([C:11](=[O:13])[CH2:12][Br:19])[NH:8][N:7]=1)=[O:5])[CH3:2]

Participants

5

Reactant 3

HCID 8028TetrahydrofuranHCID 17977687Phenyltrimethylammonium bromide dibromideHCID 178468948HCID 178468948, compound

Product 1

HCID 1784690765-(2-Bromoacetyl)pyrazole-3-carboxylic acid ethyl esterYield 145.7%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A 100ml flask was charged with 27.8 g of 5-acetylpyrazole-3-carboxylic acid ethyl ester and 40 ml of tetrahydrofuran. To this mixture, 56.4 g of phenyltrimethylammonium tribromide were added. The resulting red mixture was stirred at room temperature for 1 hour and poured into 600 ml of water. The resulting mixture was filtered and the solids were washed with more water. The solids were collected, air-dried and recrystallized from 1:1 mixture of disopropyl ether and hexanes (300ml) to afford 33.1 g of 5-(2-bromoacetyl)pyrazole-3-carboxylic acid ethyl ester as white solids, mp 174°-176° C. NMR: 1.42 (t, 3H), 4.44 (q, 2H), 4.57 (s, 2H), 7.4 (s, 1H).

Workup

  1. filtrationThe resulting mixture was filtered
  2. washthe solids were washed with more water
  3. customThe solids were collected
  4. customair-dried
  5. customrecrystallized from 1:1 mixture of disopropyl ether and hexanes (300ml)

Sources & evidence

ORD record
ord-40a3b2b9e5c448a0ad925245d4f739eb
Source dataset
uspto-grants-1995_11
Patent number
US05470862

Reaction notes

Loading…