Boron tribromide → HCID 135617184, compound

To a solution of 3-(2-methoxyphenyl)-1-methyl-1H-thieno[3,2-c]pyrazole (4.2 g) in 30 ml of dichloromethane was added dropwise 24 ml of a stock solution of BBr3 in dichloromethane. The mixture warmed up spontaneously and a precipitate began to deposit. After stirring at ambient temperature for 2 hours, the reaction mixture was quenched with 50 ml of 1N hydrochloric acid. Stirring was continued overnight whereupon the mixture became almost clear. The organic layer was diluted with ether, the phases were separated, and the aqueous layer was basified with concentrated NH3 and extracted three times with 200 ml total of ether. The combined organic solution was washed with water, dried (over anhydrous magnesium sulfate) and concentrated to a solid. Purifcation of the crude product was effected by passing it through a column of silica gel packed in dichloromethane, which afforded 3.48 g of crystals. They were further purified by recrystallization from ether/hexane, m.p. 112°-113° C.

1. temperatureThe mixture warmed up spontaneously
2. customthe reaction mixture was quenched with 50 ml of 1N hydrochloric acid
3. stirringStirring
4. waitwas continued overnight whereupon the mixture
5. additionThe organic layer was diluted with ether
6. customthe phases were separated
7. extractionextracted three times with 200 ml total of ether
8. washThe combined organic solution was washed with water
9. dry with materialdried (over anhydrous magnesium sulfate)
10. concentrationconcentrated to a solid

ORD record

ord-243bf5dbaa4147e5b14920c92db0483d

Source dataset

uspto-grants-1988_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04728651