Reaction #607466

Reaction equation

Propanoyl chloride

anthranilic acid

hydrochloric acid

→

raw product

Yield 78.2%

2-ethyl-4H-3,1-benzoxazin-4-one

Yield 78.2%

Solvents

dichloromethane

Conditions

Workup

1. 1
   Temperatureunder reflux
2. 2
   OtherAfter the end of the reaction
3. 3
   Extractionthe resulting mixture was extracted with ethyl acetate (100 mL)
4. 4
   Dryingthe extract was dried with magnesium sulfate
5. 5
   Otherthe solvent was evaporated
6. 6
   workup.ADDITIONAcetic anhydride (15 mL) was added to the residue
7. 7
   Temperatureto reflux
8. 8
   OtherAfter the end of the reaction
9. 9
   Otherthe reaction medium spin dried at a temperature of 65° C.

Procedure

Propanoyl chloride (6.2 g, 67 mmol) was added to a solution of anthranilic acid (1 g, 7.3 mmol) in dichloromethane (20 mL). The reaction medium was kept under reflux and agitation, with the end of the reaction being monitored by CG/MS. After the end of the reaction, a hydrochloric acid solution was added (20 mL, 1M), and the resulting mixture was extracted with ethyl acetate (100 mL), the extract was dried with magnesium sulfate and the solvent was evaporated. Acetic anhydride (15 mL) was added to the residue and the reaction medium was taken to reflux and accompanied through CG/MS in order to monitor cyclization. After the end of the reaction, the reaction medium spin dried at a temperature of 65° C. using portions of toluene to facilitate the elimination of the anhydride. 1.0 g of the raw product 2-ethyl-4H-3,1-benzoxazin-4-one was obtained, which was used directly in the stage subsequent to reaction.

Source