Lithium hydroxide, monohydrate → 2-(4-Fluorobenzenesulphonylamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid

HRID 1506892Notes

Reaction equation

HRID 1506892 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([NH:11][C:12]2[S:16][C:15]3[CH2:17][CH2:18][CH2:19][CH2:20][C:14]=3[C:13]=2[C:21]([O:23]CC)=[O:22])(=[O:10])=[O:9])=[CH:4][CH:3]=1.O.[OH-].[Li+]>O1CCOCC1.O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([S:8]([NH:11][C:12]2[S:16][C:15]3[CH2:17][CH2:18][CH2:19][CH2:20][C:14]=3[C:13]=2[C:21]([OH:23])=[O:22])(=[O:9])=[O:10])=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 68278868Ethyl 2-(4-fluorobenzenesulphonylamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate2×

Product 1

HCID 569621112-(4-Fluorobenzenesulphonylamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acidYield 21.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 312751,4-DioxaneSolvent

Conditions

Temperature
120 °C

Procedure

A solution of ethyl 2-(4-fluorobenzenesulphonylamino)-4,5,6,7-tetrahydro-benzo[b]thiophene-3-carboxylate (Intermediate 2, 0.12 g) and lithium hydroxide monohydrate (0.036 g) in a mixture of dioxane and water (2:1, 6 ml) was divided between two 2-5 ml microwave vials and the contents of each vial were stirred and heated in the microwave at 120° C. for 30 minutes. The two batches were combined, diluted with water and extracted with ethyl acetate. The aqueous phase was acidified to pH1 by addition of hydrochloric acid (1M) and the resultant suspension was extracted with ethyl acetate, washed with water, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica eluting with a mixture of methanol and DCM (2.5%) to give a solid which was triturated with DCM. The resultant solid was collected by filtration to give 2-(4-fluorobenzenesulphonylamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid (0.024 g) as a light orange solid.

Workup

  1. extractionextracted with ethyl acetate
  2. additionThe aqueous phase was acidified to pH1 by addition of hydrochloric acid (1M)
  3. extractionthe resultant suspension was extracted with ethyl acetate
  4. washwashed with water
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. customThe filtrate was evaporated to dryness
  8. customthe residue was purified by chromatography on silica eluting with a mixture of methanol and DCM (2.5%)
  9. customto give a solid which
  10. customwas triturated with DCM
  11. filtrationThe resultant solid was collected by filtration

Sources & evidence

ORD record
ord-cbc3c2366d794f569bab72e259ea9960
Source dataset
uspto-grants-2015_12
Patent number
US09221787B2

Reaction notes

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