Anthranilic Acid → 3-Bromo-1-methylnaphthalene

A 250 ml three-neck round bottomed flask was equipped with a reflux condenser and two addition funnels. 430 mg(2.2 mmol) of 4-bromo-6-methyl-2-pyrone prepared according to the procedure described in a literature(see: M. Cervera, Tetrahedron, 46, 7885, 1990) from 4-hydroxy-6-methyl-2-pyrone and phosphorus tribromide was dissolved in 100 ml of ethyleneglycol dimethylether(DME), which was then introduced into the flask. Catalytic amount of trifluoroacetic acid was added and the resulting mixture was heated under reflux. While refluxing, isoamylnitrite(0.48 ml, 3.4 mmol) and anthranilic acid (470 mg, 3.4 mmol) in DME which were contained in the funnels, respectively, were added dropwise simultaneously. After confirming that the starting materials were completely reacted, addition was stopped and the reaction solution was cooled. The solvent was removed under reduced pressure and the remaining materials were diluted with 250 ml of dichloromethane. The resulting solution was sequentially washed with 5% aqueous hydrochloric acid solution, 5% aqueous sodium hydroxide solution and water, and then dried over anhydrous magnesium sulfate. The solvent was removed and the residue was subjected to column chromatography(eluent: n-Hexane/ethylacetate=20/1, v/v) to give 340 mg(Yield 68%) of the title compound.

1. customA 250 ml three-neck round bottomed flask was equipped with a reflux condenser
2. additiontwo addition funnels
3. additionwhich was then introduced into the flask
4. temperaturethe resulting mixture was heated
5. temperatureunder reflux
6. temperatureWhile refluxing
7. additionrespectively, were added dropwise simultaneously
8. customwere completely reacted
9. additionaddition
10. temperaturethe reaction solution was cooled
11. customThe solvent was removed under reduced pressure
12. additionthe remaining materials were diluted with 250 ml of dichloromethane
13. washThe resulting solution was sequentially washed with 5% aqueous hydrochloric acid solution, 5% aqueous sodium hydroxide solution and water
14. dry with materialdried over anhydrous magnesium sulfate
15. customThe solvent was removed

ORD record

ord-94c85b1d7bd943798d58ecacfb67ee0e

Source dataset

uspto-grants-2003_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06511978B1