Sodium Hydroxide → Ethyl 4,5-dihydro-8-methylthio-2-phenylthieno(3,4-e]benzimidazole-6-carboxylate

HRID 2296804Notes

Reaction equation

HRID 2296804 reaction equation
[OH-].[Na+].Cl.[C:4]([NH2:12])(=[NH:11])[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.Br[CH:14]1[CH2:29][CH2:28][C:17]2=[C:18]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[S:19][C:20]([S:21][CH3:22])=[C:16]2[C:15]1=O>O.C(Cl)(Cl)Cl>[CH3:22][S:21][C:20]1[S:19][C:18]([C:23]([O:25][CH2:26][CH3:27])=[O:24])=[C:17]2[CH2:28][CH2:29][C:14]3[N:11]=[C:4]([C:5]4[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=4)[NH:12][C:15]=3[C:16]=12

Participants

6

Reactant 3

HCID 14798Sodium HydroxideHCID 80289Benzamidine, hydrochlorideHCID 15885619Ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate

Product 1

HCID 178470566Ethyl 4,5-dihydro-8-methylthio-2-phenylthieno(3,4-e]benzimidazole-6-carboxylateYield 13.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 6212ChloroformSolvent

Procedure

A solution of sodium hydroxide (1.65 g) in water (3 ml) was added to a solution of benzamidine hydrochloride (5.38 g) in water (2 ml) at room temperature; a solution of ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate (2.00 g) in chloroform (30 ml) was further added. The reaction mixture was refluxed under heating for 3 days, after which it was poured over water and extracted with ethyl acetate. The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off. The residue was subjected to silica gel column chromatography and eluted with ethyl acetate-hexane (1:2, v/v) to yield ethyl 4,5-dihydro-8-methylthio-2-phenylthieno[3,4-e]benzimidazole-6-carboxylate (0.28 g, 13.2%), which was then recrystallized from ethyl acetate-ethanol. Brown prisms. Melting point 218-219° C.

Workup

  1. temperatureThe reaction mixture was refluxed
  2. temperatureunder heating for 3 days
  3. extractionextracted with ethyl acetate
  4. washThe organic layer was washed with water
  5. dry with materialdried (MgSO4)
  6. distillationafter which the solvent was distilled off
  7. washeluted with ethyl acetate-hexane (1:2

Sources & evidence

ORD record
ord-f6749137f3ff454990cc2d90f94bab50
Source dataset
uspto-grants-2002_12
Patent number
US06489351B1

Reaction notes

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