反应详情

温度

100 °C

Diphenylphosphoryl azide (25.0 mL, 116.0 mmol, 1.5 eq) is added at room temperature to a stirred solution of 4-benzyloxy-6-methoxy-[1,5]naphthyridine-3-carboxylic acid (24.0 g, 77.34 mmol, 1.0 eq) in N,N-dimethylformamide (300 mL), followed by tert-butanol (8.5 mL, 89.71 mmol, 1.16 eq) and triethylamine (104.5 mL, 773.4 mmol, 10.0 eq). After 30 minutes stirring at 70° C. and 2 hours at 100° C., the reaction mixture is cooled down to room temperature, solvent is removed and the residue is extracted with ethyl acetate (3×200 mL) and a saturated sodium hydrogen carbonate aqueous solution (200 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to afford crude (4-benzyloxy-6-methoxy-[1,5]naphthyridin-3-yl)-carbamic acid tert-butyl ester that is directly engaged in the next step.

1. temperaturethe reaction mixture is cooled down to room temperature
2. customsolvent is removed
3. extractionthe residue is extracted with ethyl acetate (3×200 mL)
4. dry with materialThe combined organic layers are dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated