Sulfuric Acid → Ethyl 4-(3,4-dimethoxybenzoyl)-1H-1,2,3-triazole-5-carboxylate

Temperature

40 °C

Sodium azide (4.87 g, 75 mmol), sodium chlorate (2.90 g, 27 mmol), and a 37% aqueous ferric chloride solution (1.49 g, 3 mmol) were added to N,N-dimethylformamide (36 mL), the mixed solution was heated to 40° C., and a mixed solution previously prepared by adding ethyl 4-(3,4-dimethoxyphenyl)-4-oxo-2-butenoate (18 g, 68 mmol) to N,N-dimethylformamide (36 mL) and then dissolving them each other at 50° C. was added dropwise thereto. After the completion of the dropwise addition, a reaction was allowed to proceed at 40° C. for one hr, and a reaction was further allowed to proceed at 65° C. for one hr. After the completion of the reaction, the reaction solution was cooled to 5° C., and acetonitrile (7 mL) and an aqueous solution of sodium nitrite (1.18 g, 17 mmol) in water (25 mL) were successively added dropwise thereto. The mixture was adjusted to pH 1.5 by the addition of a 3 M aqueous sulfuric acid solution. The mixture was stirred at 5° C. for one hr, and ethyl acetate (198 ml) was then added thereto, followed by separation. The organic layer was washed three times with 5% brine, was dried over anhydrous magnesium sulfate, and was filtered. The filtrate was concentrated under the reduced pressure to precipitate crystals. Toluene (90 mL) was added to the residue of the concentration, and the crystals were aged at 5° C. for 12 hr. The crystals were collected by filtration, were then washed with toluene, and were dried under the reduced pressure to give 17.15 g of a light yellow powder (yield 82.5%).

1. customa mixed solution previously prepared
2. dissolutiondissolving them each other at 50° C.
3. additionwas added dropwise
4. additionAfter the completion of the dropwise addition
5. waitto proceed at 65° C. for one hr
6. customAfter the completion of the reaction
7. temperaturethe reaction solution was cooled to 5° C.
8. customfollowed by separation
9. washThe organic layer was washed three times with 5% brine
10. dry with materialwas dried over anhydrous magnesium sulfate
11. filtrationwas filtered
12. concentrationThe filtrate was concentrated under the reduced pressure
13. customto precipitate crystals
14. additionToluene (90 mL) was added to the residue of the concentration
15. waitthe crystals were aged at 5° C. for 12 hr
16. filtrationThe crystals were collected by filtration
17. washwere then washed with toluene
18. customwere dried under the reduced pressure

ORD record

ord-bd59fe30549d47df9d440051edfc3840

Source dataset

uspto-grants-2007_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07238719B2