Lithium Carbonate → 3-Oxo-2,3-dihydro[1]benzothiophene-2-spirocyclopropane

HRID 1659543Notes

Reaction equation

HRID 1659543 reaction equation
Br[CH:2]1[CH2:8][CH2:7][S:6][C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[C:3]1=[O:13].C(=O)([O-])[O-].[Li+].[Li+]>CN(C)C=O.S(C1C=CC(C)=CC=1)([O-])(=O)=O.[Ag+]>[O:13]=[C:3]1[C:7]2([CH2:8][CH2:2]2)[S:6][C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]1=2

Participants

5

Reactant 2

HCID 11125Lithium CarbonateHCID 3459534-Bromo-3,4-dihydro-1-benzothiepin-5(2H)-one

Product 1

HCID 123940523-Oxo-2,3-dihydro[1]benzothiophene-2-spirocyclopropane

Reagents, catalysts & solvents 2

HCID 85606Benzenesulfonic acid, 4-methyl-, silver(1+) salt (1:1)CatalystHCID 6228DimethylformamideSolvent

Procedure

In dry dimethylformamide, 0.5 g of 4-bromo-2,3-dihydrobenzo[b]thiepin-5(4H)-one, 0.6 g of silver tosylate and 0.2 g of lithium carbonate are heated under reflux for 12 hours, at the end of which time the reaction mixture is poured in ice-water. The resultant crystals are recovered by filtration and dried. This crude product is purified by thin-layer chromatography on silica gel (solvent system: benzene-n-hexane=1:3). The crude crystals thus obtained are recrystallized from methylene chloride-n-hexane. By the above procedure there is obtained 3-oxo-2,3-dihydro[1]-benzothiophene-2-spirocyclopropane as colorless prisms melting at 70° C.

Workup

  1. temperatureunder reflux for 12 hours, at the end of which time the reaction mixture
  2. filtrationThe resultant crystals are recovered by filtration
  3. customdried
  4. customThis crude product is purified by thin-layer chromatography on silica gel (solvent system: benzene-n-hexane=1:3)
  5. customThe crude crystals thus obtained
  6. customare recrystallized from methylene chloride-n-hexane

Sources & evidence

ORD record
ord-96ba8cb3a6de407d84a363322a73e1e3
Source dataset
uspto-grants-1981_12
Patent number
US04304784

Reaction notes

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