[CH2:1]([C:8]1[CH:16]=[C:15]([O:17][CH3:18])[CH:14]=[CH:13][C:9]=1[C:10]([OH:12])=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C[N:20]([CH:22]=O)C.[C:24](Cl)(=O)C(Cl)=O>C(Cl)Cl>[CH2:1]([C:8]1[CH:16]=[C:15]([O:17][CH3:18])[CH:14]=[CH:13][C:9]=1[C:10]([NH:20][CH2:22][CH3:24])=[O:12])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1To a 0 C solution of 2-benzyl-4-methoxybenzoic acid (5 g) in 250 mL CH2Cl2 were added a catalytic amount of DMF and a solution of oxalyl chloride (2 mL) in 40 mL CH2Cl2. The reaction was warmed to room temp and stirred overnight, then concentrated to dryness and azeotroped from toluene (2×). The residue was dissolved in 50 mL THF and added dropwise to a 0 C solution of ethylamine (10 mL, 70% aqueous solution) in 200 mL THF. The reaction was warmed to room temp and stirred for 2 h, then quenched with saturated aqueous KHSO4 solution and extracted with EtOAc (2×). The organic solutions were dried (Na2SO4) and concentrated, then triturated with hexanes to give 5.2 g of 2-benzyl-N-ethyl-4-methoxybenzamide.
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