Boron tribromide → HCID 135617184, compound

HRID 622212Notes

Reaction equation

HRID 622212 reaction equation
C[O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[C:9]1[C:10]2[S:17][CH:16]=[CH:15][C:11]=2[N:12]([CH3:14])[N:13]=1.B(Br)(Br)Br>ClCCl>[OH:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[C:9]1[C:10]2[S:17][CH:16]=[CH:15][C:11]=2[N:12]([CH3:14])[N:13]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 14097245HCID 14097245, compound

Product 1

HCID 135617184HCID 135617184, compoundYield 87.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

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 begain to deposit. After stirring at ambient temperature for 2 hours, the reaction mixture was quenched with 50 ml of 1H 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. Purification 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.

Workup

  1. temperatureThe mixture warmed up spontaneously
  2. customthe reaction mixture was quenched with 50 ml of 1H 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
  11. customPurification of the crude product

Sources & evidence

ORD record
ord-edb70282bdb248888a7e31d98d814fb2
Source dataset
uspto-grants-1988_09
Patent number
US04769472

Reaction notes

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