反应 #2314343

反应方程式

6-amino-3-bromo-2-methylpyridine

diethoxymethylenemalonate

→

desired product

收率 35.0%

Ethyl 6-bromo-4-hydroxy-7-methyl[1,8]naphthyridine-3-carboxylate

收率 35.0%

反应条件

后处理

1. 1
   温度The reaction is cooled
2. 2
   其他the residue is recrystallized from EtOH
3. 3
   workup.DISSOLUTIONTo the resulting solid is dissolved in 45 mL of Ph2O
4. 4
   温度The solution is then cooled to room temperature
5. 5
   其他the resulting precipitate is collected
6. 6
   其他dried
7. 7
   其他The crude product is chromatographed on silica (Biotage flash 40M, 2% MeOH/CH2Cl2 eluent)
8. 8
   其他Fractions homogeneous by TLC are collected
9. 9
   浓缩concentrated

实验过程

A solution of 6-amino-3-bromo-2-methylpyridine (1.89 g) and diethoxymethylenemalonate (2.16 g) is heated at 110° C. for 30 min. The reaction is cooled and the residue is recrystallized from EtOH. To the resulting solid is dissolved in 45 mL of Ph2O. The mixture is heated to 250° C. for 3 h. The solution is then cooled to room temperature and the resulting precipitate is collected and dried. The crude product is chromatographed on silica (Biotage flash 40M, 2% MeOH/CH2Cl2 eluent). Fractions homogeneous by TLC are collected and concentrated to yield 1.075 g (35%) of the desired product as a yellow solid. Physical characteristics are as follows: m.p. 270° C. (dec.); 1H NMR (DMSO-d6) δ 12.73, 8.49, 8.47, 4.21, 2.67, 1.27.

来源