Hydrochloric Acid → N-(2-fluorophenyl)-2-oxo-2,3-dihydro-3-benzo[b]thiophenecarboxamide

HRID 434353Notes

Reaction equation

HRID 434353 reaction equation
[O:1]=[C:2]1[S:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[CH2:3]1.[H-].[Na+].[F:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[NH:20][C:21](=O)[O:22]C1C=CC=CC=1.Cl>CN(C)P(=O)(N(C)C)N(C)C>[F:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[NH:20][C:21]([CH:3]1[C:2](=[O:1])[S:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]1=2)=[O:22]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 24758Sodium hydrideHCID 591560Benzo[b]thiophen-2(3H)-oneHCID 3790948phenyl N-(2-fluorophenyl)carbamate

Product 1

HCID 12799381N-(2-fluorophenyl)-2-oxo-2,3-dihydro-3-benzo[b]thiophenecarboxamide

Reagents, catalysts & solvents 1

HCID 12679HexamethylphosphoramideSolvent2×

Procedure

A solution of 50 g of 2,3-dihydro-2-oxo-benzo[b]thiophene in 200 ml of hexamethylphosphoric acid triamide is added dropwise to a suspension of 16 g of a 50% strength sodium hydride/mineral oil dispersion in 500 ml of hexamethylphosphoric acid triamide, whilst cooling, the temperature being kept below 15°. After stirring for one hour at room temperature, 77 g of phenyl N-(2-fluorophenyl)-carbamate are added in portions, with external cooling. The reaction mixture is stirred for a further 16 hours at room temperature and poured into a mixture of 300 ml of 2 N hydrochloric acid and 3,000 ml of ice water. An oil separates out and this crystallises after about 2 hours. The crystalline product, in which solvent is incorporated, is dissolved in 1,000 ml of diethyl ether and the solution is washed with water. The organic phase is separated off, dried over sodium sulphate and evaporated to dryness. The crude product is recrystallised from diethyl ether and gives N-(2-fluorophenyl)-2-oxo-2,3-dihydro-3-benzo[b]thiophenecarboxamide, melting point 155°-156°.

Workup

  1. temperaturewhilst cooling
  2. custombeing kept below 15°
  3. stirringThe reaction mixture is stirred for a further 16 hours at room temperature
  4. customthis crystallises after about 2 hours
  5. dissolutionis dissolved in 1,000 ml of diethyl ether
  6. washthe solution is washed with water
  7. customThe organic phase is separated off
  8. dry with materialdried over sodium sulphate
  9. customevaporated to dryness
  10. customThe crude product is recrystallised from diethyl ether

Sources & evidence

ORD record
ord-200749afbc2c43d0aaf759c87dddd638
Source dataset
uspto-grants-1983_08
Patent number
US04396621

Reaction notes

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