반응 #417958

반응 방정식

2-Amino-5-methylbenzoic acid

pyridine

chloroformate

Methyl chloroformate

→

solid

수율 31.0%

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

수율 31.0%

용매

pentane

ethyl acetate

반응 조건

후처리

1. 1
   기타prepared above
2. 2
   workup.WAITthe mixture was left
3. 3
   workup.STIRRINGto stir at ambient temperature overnight
4. 4
   세척washed with water (15 ml) and 10% aqueous citric acid (20 ml)
5. 5
   추출The combined aqueous phases were extracted with ethyl acetate (20 ml)
6. 6
   세척washed with water (20 ml) and brine (20 ml)
7. 7
   농축then concentrated
8. 8
   기타to give a solid
9. 9
   여과filtered
10. 10
    여과filtered
11. 11
    기타purified by flash chromatography on silica (1.5% diisopropylethylamine in dichloromethane)

실험 절차

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.

출처