N-bromobutanimide → Bromo[(4-chlorophenyl)hydrazono]acetic acid methyl ester

HRID 860822Notes

Reaction equation

HRID 860822 reaction equation
[CH3:1][O:2][C:3](=[O:14])[CH:4]=[N:5][NH:6][C:7]1[CH:12]=[CH:11][C:10]([Cl:13])=[CH:9][CH:8]=1.[Br:15]N1C(=O)CCC1=O>C1COCC1>[CH3:1][O:2][C:3](=[O:14])[C:4]([Br:15])=[N:5][NH:6][C:7]1[CH:12]=[CH:11][C:10]([Cl:13])=[CH:9][CH:8]=1

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 69446891[(4-Chlorophenyl)hydrazono]acetic acid methyl ester

Product 1

HCID 73712138Bromo[(4-chlorophenyl)hydrazono]acetic acid methyl esterYield 84.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of [(4-chlorophenyl)hydrazono]acetic acid methyl ester (30, 13.0 g, 61.2 mmol) in anhydrous THF (100 mL) was treated with N-bromosuccinimide (NBS, 11.97 g, 67.3 mmol, 1.1 equiv) at 0–5° C. under N2, and the resulting reaction mixture was stirred at 0–5° C. for an additional 30 min. When HPLC and TLC showed the reaction was deemed complete, the solvent removed in vacuo. The residue was directly purified by column chromatography (SiO2, 0–15% EtOAc/hexane gradient elution) to afford the desired bromo[(4-chlorophenyl)hydrazono]acetic acid methyl ester (31, 15.0 g, 17.84 g theoretical, 84%) as pale-yellow solids, which was found to be essentially pure to do the following cycloaddition reaction without further purification. For 31, CIMS m/z 290/292 (M+−H, C9H8BrClN2O2).

Workup

  1. customthe resulting reaction mixture
  2. customthe solvent removed in vacuo
  3. customThe residue was directly purified by column chromatography (SiO2, 0–15% EtOAc/hexane gradient elution)

Sources & evidence

ORD record
ord-22927df627634d689a6b117746ac14cd
Source dataset
uspto-grants-2006_12
Patent number
US07153960B2

Reaction notes

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