反应 #1256757

反应方程式

2-Amino-5-methylbenzoic acid

pyridine

chloroformate

Methyl chloroformate

→

solid

收率 31.0%

2-Hexadecyloxy-6-methyl-4H-3,1-benzoxazin-4-one

收率 31.0%

溶剂

pentane

ethyl acetate

反应条件

后处理

1. 1
   其他prepared above
2. 2
   workup.WAITthe mixture was left
3. 3
   workup.STIRRINGto stir at ambient temperature overnight
4. 4
   洗涤washed with water (15 ml) and 10% aqueous citric acid (20 ml)
5. 5
   萃取The combined aqueous phases were extracted with ethyl acetate (20 ml)
6. 6
   洗涤washed with water (20 ml) and brine (20 ml)
7. 7
   浓缩then concentrated
8. 8
   其他to give a solid
9. 9
   过滤filtered
10. 10
    过滤filtered
11. 11
    其他purified by flash chromatography on silica (1.5% diisopropylethylamine in dichloromethane)

实验过程

2-Amino-5-methylbenzoic acid (2.71 g, 17.9 mmol, 0.87 eq.) was dissolved in pyridine (24 ml) and added to the chloroformate solution prepared above. The mixture was stirred at room temperature for 1.75 hours. Methyl chloroformate (13.6 ml, 176 mmol, 8.5 eq) was added slowly, then the mixture was left to stir at ambient temperature overnight. The mixture was diluted with ethyl acetate (20 ml) and washed with water (15 ml) and 10% aqueous citric acid (20 ml). The combined aqueous phases were extracted with ethyl acetate (20 ml). The organic extracts were combined and washed with water (20 ml) and brine (20 ml) then concentrated to give a solid. This was slurried in pentane (5 ml), filtered, then slurried in acetonitrile (5 ml), filtered and purified by flash chromatography on silica (1.5% diisopropylethylamine in dichloromethane) to give a white solid (2.51 g, 31%) δH (400 MHz, CDCl3) 0.87 (3H, t, J 6.8, CH2CH3), 1.24-1.45 (26H, m, 13×CH2), 1.75-1.83 (2H, m, OCH2CH2), 2.41 (3H, s, ArCH3), 4.41 (2H, t, J 6.7, OCH2), 7.30 (1H, d, J 8.3, ArH), 7.51 (1H, dd, J 8.5, 2.0, ArH), 7.90 (1H, d, J 1.1, ArH); m/z (ES+) 402 (MH+); MPt. 72-73° C.

来源