Sodium Azide → Ethyl 5-azido-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo(c]thiophene-1-carboxylate

HRID 2296794Notes

Reaction equation

HRID 2296794 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:18].[N-:19]=[N+:20]=[N-:21].[Na+]>CN(C)C=O.O>[N:19]([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:18])=[N+:20]=[N-:21]

Participants

5

Reactant 2

HCID 33557Sodium AzideHCID 15885619Ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate

Product 1

HCID 18388306Ethyl 5-azido-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo(c]thiophene-1-carboxylateYield 80.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6228DimethylformamideSolvent

Procedure

Ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate (5.24 g) was suspended in N,N-dimethylformamide (80 ml); a solution of sodium azide (1.95 g) in water (12 ml) was added at 0° C. After the reaction mixture was stirred at room temperature for 4 hours, it was poured over 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 (1:9 to 1:2, v/v) to yield ethyl 5-azido-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate (3.77 g, 80.7%), which was then recrystallized from ethyl acetate-hexane. Colorless needles. Melting point 163-164° C. (decomposed).

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic layer was washed with water
  3. dry with materialdried (MgSO4)
  4. distillationafter which the solvent was distilled off
  5. washeluted with ethyl acetate-hexane (1:9 to 1:2

Sources & evidence

ORD record
ord-59f621679b0d433db3dadcfb621ab58e
Source dataset
uspto-grants-2002_12
Patent number
US06489351B1

Reaction notes

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