Acetic Acid → HCID 18537078, compound

HRID 2298628Notes

Reaction equation

HRID 2298628 reaction equation
[C:1]([C:5]1[CH:9]=[C:8](C(Cl)=O)[N:7]([CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[N:6]=1)([CH3:4])([CH3:3])[CH3:2].C[Si](C=[N+]=[N-])(C)C.[BrH:27].[C:28]([OH:31])(=O)[CH3:29]>C(#N)C>[C:1]([C:5]1[CH:9]=[C:8]([C:28](=[O:31])[CH2:29][Br:27])[N:7]([CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[N:6]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 260Hydrogen BromideHCID 167693TrimethylsilyldiazomethaneHCID 27993221-benzyl-3-tert-butyl-1H-pyrazole-5-carbonyl chloride

Product 1

HCID 18537078HCID 18537078, compound

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A solution of 1 g (3.6 mmol) of 3-(tert-butyl)-1-benzylpyrazole-5-carbonyl chloride (Maybridge, Cornwall, UK) was dissolved in dry acetonitrile (4 mL) and 4.5 mL (9 mmol) of 2 M trimethylsilyldiazomethane in hexanes (Aldrich, Milwaukee, Wis., USA) was added. After stirring 1 h 20 min at room temperature, the mixture was cooled on an ice bath for 5 min. To this, 30% hydrogen bromide in acetic acid (2 mL, 10 mmol) was added dropwise over 15 min. This was stirred an additional 15 minutes on an ice bath. Filtration of the precipitated solid and evaporation of the solvents gave 1-[3-(tert-butyl)-1-benzylpyrazol-5-yl]-2-bromoethan-1-one (1.47 g, quantitive yield) as an orange solid. 1H-NMR (DMSO-d6; 300 MHz) δ7.33-7.06 (m, 5H), 7.08 (s, 1H), 5.64 (s, 2H), 4.57 (s, 2H), 1.28 (s, 9H). Mass spectrum (MALDI-TOF, CHCA matrix, m/z): Calcd. for C16H19N2OBr, 335.1 and 337.1 (M+H), found 335.6 and 337.6.

Workup

  1. temperaturethe mixture was cooled on an ice bath for 5 min
  2. stirringThis was stirred an additional 15 minutes on an ice bath
  3. filtrationFiltration of the precipitated solid and evaporation of the solvents

Sources & evidence

ORD record
ord-65807bceb76d4aefa509376736f0a9a5
Source dataset
uspto-grants-2002_12
Patent number
US06492403B1

Reaction notes

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