Pyridine → 2-Bromo-6-(2-chloroacetamido)benzoic acid

反応式

[NH2:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]([Br:11])[C:3]=1[C:4]([OH:6])=[O:5].N1C=CC=CC=1.[Cl:18][CH2:19][C:20](Cl)=[O:21]>C1(C)C=CC=CC=1>[Br:11][C:7]1[CH:8]=[CH:9][CH:10]=[C:2]([NH:1][C:20](=[O:21])[CH2:19][Cl:18])[C:3]=1[C:4]([OH:6])=[O:5]

参加物

実験手順

To a stirred solution of 2-amino-6-bromo-benzoic acid (6) (3.06 g, 14.2 mmol) in toluene (75 mL) cooled to 0° C. in an ice-bath was added pyridine (0.60 mL, 7.10 mmol) followed by a solution of chloroacetyl chloride (2.26 mL, 28.4 mmol) in toluene (75 mL) drop-wise over 1 hr. The reaction mixture was allowed to warm to RT, and was heated at 115° C. for 3 hr and then allowed to cool to RT. The solvent volume was reduced by half by evaporation in vacuo. Upon standing overnight, the product precipitated and was collected by filtration to afford 2-bromo-6-(2-chloroacetamido)benzoic acid (7a) (1.44 g) as a white solid: m/z 290/292 (M+H)+ (ES+). The filtrate was concentrated in vacuo and the residue triturated with ethanol/heptane to afford 2-bromo-6-(2-hydroxyacetamido)benzoic acid (7b) (1.02 g, combined yield, 59%): m/z 274/276 (M+H)+ (ES+). Both 7a and 7b can be used without further purification in the next step.