C(Cl)(=O)C(Cl)=O.[CH3:7][O:8][C:9]1[C:10]([N+:18]([O-:20])=[O:19])=[C:11]([CH:15]=[CH:16][CH:17]=1)[C:12]([OH:14])=O.[CH2:21]([O:23][CH:24]([O:27][CH2:28][CH3:29])[CH2:25][NH2:26])[CH3:22].C(N(CC)CC)C>ClCCl.CN(C)C=O>[CH2:21]([O:23][CH:24]([O:27][CH2:28][CH3:29])[CH2:25][NH:26][C:12](=[O:14])[C:11]1[CH:15]=[CH:16][CH:17]=[C:9]([O:8][CH3:7])[C:10]=1[N+:18]([O-:20])=[O:19])[CH3:22]Oxalyl chloride (34 mL, 0.395 mol) was added to a solution of 3-methoxy-2-nitrobenzoic acid (60 g, 0.305 mol) in dry dichloromethane (600 mL), followed by N,N-dimethylformamide (0.6 mL, 7.8 mmol), which initiates mild gas evolution. The mixture was stirred at room temperature for two hours, then concentrated under vacuum to remove volatiles. The crude acid chloride was dissolved in dry dichloromethane (150 mL) then added dropwise to a cooled (5° C.) solution of aminoacetaldehyde diethylacetal (48 mL, 0.33 mol) and triethylamine (52 mL, 0.374 mol) in dry dichloromethane (250 mL). The mixture was stirred at room temperature for two hours, then washed with saturated aqueous sodium bicarbonate (2×100 mL) and brine (100 mL). The organics were dried over sodium sulfate and concentrated to give N-(2,2-diethoxyethyl)-3-methoxy-2-nitrobenzamide (296a, 92 g, 97% yield) as a yellow solid. MS: 335 [M+1].
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