تفاعل #417958

معادلة التفاعل

2-Amino-5-methylbenzoic acid

pyridine

chloroformate

Methyl chloroformate

→

solid

المردود 31.0%

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

المردود 31.0%

المذيبات

pentane

ethyl acetate

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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.

المصدر