反应详情

7.7 ml of triethylamine (55 mmol) were added dropwise to a suspension of 10.0 g of ethyl 2-amino-4-nitrobenzoate hydrochloride (4.3 mmol) in 100 ml of acetone. Subsequently, 6.55 ml of methylmalonyl chloride (52 mmol) were added. The reaction mixture was left to stir at room temperature for 48 hrs., concentrated and then treated with a solution of 4.2 g of sodium (183 mmol) in 110 ml of ethanol. The reaction mixture was boiled at reflux for 2.5 hrs. After removing the solvent the residue was taken up in 200 ml of water and heated to 60° C. for 1 hr. Subsequently, the mixture was filtered over Dicalite and thereafter the pH value was adjusted to pH=3.5 with 3N HCl. The precipitate which thereby separated was filtered off, washed with water and dried in a high vacuum. There were obtained 7.2 g of ethyl 4-hydroxy-7-nitro-2-oxo-1,2-dihydro-quinoline-3-carboxylate (60%) as beige crystals.

1. waitThe reaction mixture was left
2. concentration, concentrated
3. temperatureat reflux for 2.5 hrs
4. customAfter removing the solvent the residue
5. temperatureheated to 60° C. for 1 hr
6. filtrationSubsequently, the mixture was filtered over Dicalite
7. customThe precipitate which thereby separated
8. filtrationwas filtered off
9. washwashed with water
10. customdried in a high vacuum