2-(1,2-Dibromoethyl)pyridine hydrobromide → 2,3-Dihydro-5-methyl-2-(2-pyridyl)thiazolo[3,2-a]-benzimidazole

HRID 2351294Notes

Reaction equation

HRID 2351294 reaction equation
[CH3:1][C:2]1[C:10]2[NH:9][C:8]([SH:11])=[N:7][C:6]=2[CH:5]=[CH:4][CH:3]=1.CC(C)([O-])C.[K+].Br.Br[CH:20]([C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][N:24]=1)[CH2:21]Br>CC(O)(C)C.Cl>[CH3:1][C:2]1[C:10]2[N:9]3[CH2:21][CH:20]([C:23]4[CH:28]=[CH:27][CH:26]=[CH:25][N:24]=4)[S:11][C:8]3=[N:7][C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 198460922-(1,2-Dibromoethyl)pyridine hydrobromideHCID 23665647Potassium tert-butoxideHCID 178424004HCID 178424004, compound

Product 1

HCID 198460952,3-Dihydro-5-methyl-2-(2-pyridyl)thiazolo[3,2-a]-benzimidazoleYield 7.2%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 6386tert-ButanolSolvent

Procedure

4-Methyl-2-mercaptobenzimidazole (13.32 g) was suspended in 2-methylpropan-2-ol (150 ml) and potassium tertbutoxide (9.04 g) added. The mixture was stirred for 2 hours and 2-(1,2-dibromoethyl)pyridine hydrobromide (27.68 g) added. The mixture was stirred at ambient temperature for 1 hour and then at reflux for 2 hours. The reaction mixture was filtered and the solid washed with ether. The filtrate was evaporated to dryness under reduced pressure and the residue combined with the first solid obtained. The combined material was dissolved in 2N HCl (100 ml). The aqueous solution was extracted with ethyl acetate, basified (Na2CO3) and extracted with dichloromethane. The organic layer was dried (MgSO4) and the solvent removed under reduced pressure. The residue was purified on Florisil using chloroform as eluent and on silica using ethyl acetate as eluent to give the title compound (1.55 g) mp 128°-130° C.

Workup

  1. stirringThe mixture was stirred at ambient temperature for 1 hour
  2. temperatureat reflux for 2 hours
  3. filtrationThe reaction mixture was filtered
  4. washthe solid washed with ether
  5. customThe filtrate was evaporated to dryness under reduced pressure
  6. customobtained
  7. extractionThe aqueous solution was extracted with ethyl acetate
  8. extractionextracted with dichloromethane
  9. dry with materialThe organic layer was dried (MgSO4)
  10. customthe solvent removed under reduced pressure
  11. customThe residue was purified on Florisil

Sources & evidence

ORD record
ord-3c7b762028e947c5b1f691bc9be9009b
Source dataset
uspto-grants-1989_10
Patent number
US04873237

Reaction notes

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