Bromine → HCID 15718183, compound

HRID 1646201Notes

Reaction equation

HRID 1646201 reaction equation
[C:1]([C:4]1[N:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]2=[N:6][CH:5]=1)(=[O:3])[CH3:2].[BrH:13].C(O)(=O)C.BrBr>C(O)(=O)C>[Br:13][CH2:2][C:1]([C:4]1[N:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]2=[N:6][CH:5]=1)=[O:3]

Participants

5

Reactant 3

HCID 24408BromineHCID 157181821-(Imidazo[1,2-a]pyridin-3-yl)ethan-1-oneHCID 21893785Acetic Acid Mixture with Hydrobromic Acid

Product 1

HCID 15718183HCID 15718183, compoundYield 40%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
40 °C

Procedure

22.1 g of 3-acetylimidazo[1,2-a]pyridine was dissolved in 220 ml of acetic acid. 35.1 ml of a 30% hydrogen bromide/acetic acid solution was added dropwise to the solution at 0° C. Then 28.6 g of bromine was added dropwise thereto at 40° C. The mixture was stirred at 40° C. for 2 h and crystals thus formed were filtered. The crystals were dissolved in 100 ml of water. The solution was made alkaline with an excess of an aqueous sodium hydrogencarbonate solution and then extracted with ethyl acetate. The organic layer was concentrated and the obtained brown solid was purified according to silica gel column chromatography (eluted with ethyl acetate) to obtain 13.5 g (yield: 40%) of 3-bromoacetylimidazo[1,2-a]pyridine (yield: 40%) in the form of yellow crystals. ii) A suspension comprising 1.91 g (6.0 mmol) of 4-(4-methylsulfonylaminobenzoyl)piperidine hydrochloride, 3.0 g of potassium carbonate and 40 ml of dimethylformamide was stirred at 80° C. for 1 h. After cooling to room temperature, 1.99 g of 3-bromoacetylimidazo[1,2-a]pyridine prepared in the above step i) was added thereto and the mixture was stirred at room temperature for 6 h. The reaction mixture was filtered and the filtrate was concentrated to obtain a solid residue, which was then purified according to silica gel column chromatography (chloroform:methanol=96:4). The purified product was converted into its dihydrochloride with ethanolic hydrogen chloride and recrystallized from methanol/acetone to obtain 1.75 g (yield: 58%) of the intended compound.

Workup

  1. customat 40° C
  2. customcrystals thus formed
  3. filtrationwere filtered
  4. dissolutionThe crystals were dissolved in 100 ml of water
  5. extractionextracted with ethyl acetate
  6. concentrationThe organic layer was concentrated
  7. customthe obtained brown solid was purified
  8. washaccording to silica gel column chromatography (eluted with ethyl acetate)

Sources & evidence

ORD record
ord-7a64a1c89a0541c996e46d24e931c1a1
Source dataset
uspto-grants-1993_01
Patent number
US05179095

Reaction notes

Loading…