反应详情

In a 500 ml single-necked round-bottomed flask, 230 ml of a 65% ageous HNO3 solution is added and stirred under cooling (ice/water cooling bath). 7.00 g of 3-bromo-6-methyl-pyridin-2-ol 2 at ambient temperature is introduced portion-wise. Stirring is continued for 3.5 hours at ambient temperature. After pouring the mixture into 200 ml of an ice/water mixture (pH 1), the water phase is extracted with AcOEt. The organic phase is washed twice with water brought to pH 4 by adding ageous NaOH solution (pH meter), then dried over sodium sulfate, filtered and concentrated in vacuo to give 7.52 g of a yellow solid. This crude material is suspended in diethyl ether and stirred for 1 hour at ambient temperature, filtered, washed with the same solvent and dried to give 3.89 g of the compound as a yellow-orange solid (m.p. >220° C.).

1. stirringStirring
2. extractionthe water phase is extracted with AcOEt
3. washThe organic phase is washed twice with water
4. additionby adding ageous NaOH solution (pH meter)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo