Thioacetamide → Ethyl 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-e]benzothiazole-6-carboxylate

HRID 2296796Notes

Reaction equation

HRID 2296796 reaction equation
Br[CH:2]1[CH2:17][CH2:16][C:5]2=[C:6]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[S:7][C:8]([S:9][CH3:10])=[C:4]2[C:3]1=O.[C:19]([NH2:22])(=[S:21])[CH3:20]>C(O)C>[CH3:20][C:19]1[S:21][C:2]2[CH2:17][CH2:16][C:5]3=[C:6]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[S:7][C:8]([S:9][CH3:10])=[C:4]3[C:3]=2[N:22]=1

Participants

4

Reactant 2

HCID 2723949ThioacetamideHCID 15885619Ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate

Product 1

HCID 15885620Ethyl 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-e]benzothiazole-6-carboxylateYield 44.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate (2.09 g), thioacetamide (0.90 g) and ethanol (100 ml) was refluxed under heating for 7 hours, after which it was concentrated under reduced pressure, diluted with water (50 ml) 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 (1:19 to 1:9, v/v) to yield ethyl 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-e]benzothiazole-6-carboxylate (0.86 g, 44%), which was then recrystallized from ethyl acetate-hexane. Yellow prisms. Melting point 143-144° C.

Workup

  1. temperaturewas refluxed
  2. temperatureunder heating for 7 hours
  3. concentrationafter which it was concentrated under reduced pressure
  4. additiondiluted with water (50 ml)
  5. extractionextracted with ethyl acetate
  6. washThe organic layer was washed with water
  7. dry with materialdried (MgSO4)
  8. distillationafter which the solvent was distilled off
  9. washeluted with ethyl acetate-hexane (1:19 to 1:9, v/v)

Sources & evidence

ORD record
ord-902dbf36ab194f1ea21bd905a491d9c8
Source dataset
uspto-grants-2002_12
Patent number
US06489351B1

Reaction notes

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