Reaktion #460299

Reaktionsgleichung

EtOAc hexane

triethyl amine

2-amino-5-methylbenzoic acid

valeryl chloride

→

white crystaline solid

Ausbeute 25.0%

2-Butyl-6-methylquinazolin-4(1H)-one

Ausbeute 25.0%

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated to 110° C.
2. 2
   workup.ADDITIONwas added cautiously
3. 3
   TemperaturHeating
4. 4
   Sonstigeconsumption of the quinoxazolone and formation of the polar (rf=0.4, 40%EtOAc/hexane) quinazolin-4(1H)-one
5. 5
   EinengenThe reaction mixture was concentrated in vacuo
6. 6
   FiltrationThe mixture was filtered
7. 7
   Waschenafter washing the residue with 20 mL of ether
8. 8
   SonstigeThe residue was recrystallized from MeOH

Vorschrift

To a solution of 3.0 g (20 mmol) of 2-amino-5-methylbenzoic acid in 20 mL of dry DMF at 0° C. was added 200 mg of DMAP followed by 6.07 g (60 mmol) of triethyl amine and 5.02 g (40 mmol) of valeryl chloride. The resulting mixture was stirred at 0° C. for 30 minutes. The mixture was heated to 110° C. and monitored by TLC for the formation of the intermediate quinoxazolone (rf=0.8, 40%EtOAc/hexane). Following complete formation of the intermediate 10 g (100 mmol) of NH4CO3 was added cautiously. Heating was continued to ensure consumption of the quinoxazolone and formation of the polar (rf=0.4, 40%EtOAc/hexane) quinazolin-4(1H)-one. The reaction mixture was concentrated in vacuo and the residue was taken up in 50 mL of ether and 50 mL of water. The mixture was filtered and the filtrate discarded after washing the residue with 20 mL of ether. The residue was recrystallized from MeOH to give 1.07 g (5 mmol) of a white crystaline solid. 25% yield overall. 1H-NMR (CDCl3): 0.94 (t, 3H, J=6.7 Hz), 1.50 (m, 2H), 1.83 (m, 2H), 2.49 (s, 3H), 2.78 (t, 2H), 7.60 (m, 2H), 8.05 (m, 1H). Anal (C13H16N2O), C, H, N.

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