反应详情

To a solution of 4-methoxy-4-oxobutanoic acid (14.6 g, 110.6 mmol) in toluene (530 mL) was added diphenylphosphoryl azide (30.4 g, 110.5 mmol) followed by triethylamine (18.3 g, 181.2 mmol). The reaction was stirred at RT for 30 min then 2-amino-5-bromonicotinic acid (15.9 g, 73.61 mmol) was added. The reaction was refluxed for 6 h, cooled to RT then diluted with EA (530 mL) and washed with brine (2×300 mL). The combined aqueous layers were acidified to PH 5 by adding aq. 2N HCl and a solid formed which was filtered off. The solid was dried to give 5-bromo-2-(3-(3-methoxy-3-oxopropyl)ureido)nicotinic acid (15 g, 39.3% yield) as pale yellow solid. LCMS: MH+ 347 and TR=1.047 min. Used without further purification.

1. temperatureThe reaction was refluxed for 6 h
2. temperaturecooled to RT
3. washwashed with brine (2×300 mL)
4. additionby adding aq. 2N HCl
5. customa solid formed which
6. filtrationwas filtered off
7. customThe solid was dried