Pyridine → N4-[2-(3-tert-Butoxycarbonylaminopropoxy)-4-methoxybenzoyl]-N3-(4-methoxybenzoyl)-3,4-pyridinediamine

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Reaction Steps

2-(3-tert-Butoxycarbonylaminopropoxy)-4-methoxybenzoic acid (1.6 g, 4.94 mmol) was dissolved in dry dichloromethane (20 mL) and DMF (0.5 mL) under nitrogen atmosphere. Oxalyl chloride (0.475 mL, 5.43 mmol) was added via syringe. Vigorous bubbling occurred. The mixture was stirred until gas evolution ceased, then concentrated in vacuo. The residue was dissolved in amylene-stabilized chloroform (20 mL), transferred to an addition funnel, then added dropwise over 2 hours to an ice cold solution of N3-(4-methoxybenzoyl)-3,4-pyridinediamine (1.0 g, 4.11 mmol) in amylene-stabilized chloroform (30 mL) and pyridine (2 mL, 24.7 mmol). The mixture was allowed to warm to room temperature and stir for 2.5 days. The resulting slurry was diluted with dichloromethane (50 mL) and washed twice with saturated NaHCO3, once with brine, then dried and concentrated in vacuo. Purification on a 6 mm chromatotron rotor with isocratic 96:3:1 CHCl3:MeOH:triethylamine yielded about 80% pure material that was carried on directly.

Provenance & Evidence