反応 #344999

反応方程式

EtOAc hexane

triethylamine

2-amino-5-methyl benzoic acid

valeryl chloride

→

title compound

収率 25.0%

2-n-butyl-6-methylquinazolin-4(1H)-one

収率 25.0%

溶媒

DMF

反応条件

後処理

1. 1
   温度The mixture was heated to 110° C.
2. 2
   workup.ADDITIONwas added cautiously
3. 3
   温度Heating
4. 4
   その他consumption of the quinoxazolone and formation of the polar (Rf =0.4, 40% EtOAc/hexane) quinazolin-4(1H)-one
5. 5
   濃縮The reaction mixture was concentrated in vacuo
6. 6
   ろ過The mixture was filtered
7. 7
   洗浄after washing the residue with 20 mL of ether
8. 8
   その他The residue was recrystalized from MeOH

実験手順

To a solution of 3.0 g (20 mmol) of 2-amino-5-methyl benzoic acid in 20 mL of dry DMF at 0° C. was added 200 mg of DMAP followed by 6.07 g (60 mmol) of triethylamine and 5.02 g (40 mmol) of valeryl chloride. The resulting mixture was stirred at 0° C. for 30 min. 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 (NH4)2CO3 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 recrystalized from MeOH to give 1.07 g (25%) of the title compound as a white crystalline solid.

出典