p-Toluenesulfonic acid monohydrate → 2-(4-Chloro-phenyl)-4,5-dihydro-thieno[2,3-c]pyran-7-one

HRID 2384865Notes

Reaction equation

HRID 2384865 reaction equation
C[O:2][C:3]([C:5]1[S:6][C:7]([C:13]2[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=2)=[CH:8][C:9]=1[CH2:10][CH2:11][OH:12])=O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1.C(OCC)(=O)C>[Cl:19][C:16]1[CH:17]=[CH:18][C:13]([C:7]2[S:6][C:5]3[C:3](=[O:2])[O:12][CH2:11][CH2:10][C:9]=3[CH:8]=2)=[CH:14][CH:15]=1

Participants

5

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 689499765-(4-Chloro-phenyl)-3-(2-hydroxy-ethyl)-thiophene-2-carboxylic acid methyl ester

Product 1

HCID 689489532-(4-Chloro-phenyl)-4,5-dihydro-thieno[2,3-c]pyran-7-oneYield 43%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

Dissolve 5-(4-chloro-phenyl)-3-(2-hydroxy-ethyl)-thiophene-2-carboxylic acid methyl ester (3.4 g, 11.46 mmol) in toluene (60 mL) and add p-toluenesulfonic acid monohydrate (0.3 g, 1.58 mmol) and heat to 80° C. for one hour. Cool the mixture to room temperature and dilute with ethyl acetate (50 mL). Wash the solution with 1 N NaOH and extract the aqueous portion twice with ethyl acetate. Combine the organic fractions, dry over Na2SO4, filter, and concentrate. Triturate the solid with ether and then filter and dry under vacuum to give 1.3 g (43%) of the title compound. LC-MS/ES m/z (35Cl) 265.0 [M+H]+.

Workup

  1. temperatureCool the mixture to room temperature
  2. washWash the solution with 1 N NaOH
  3. extractionextract the aqueous portion twice with ethyl acetate
  4. dry with materialdry over Na2SO4
  5. filtrationfilter
  6. concentrationconcentrate
  7. customTriturate the solid with ether
  8. filtrationfilter
  9. customdry under vacuum

Sources & evidence

ORD record
ord-5a9183086b4b4ae987c3acfffa42056a
Source dataset
uspto-grants-2012_09
Patent number
US08263772B2

Reaction notes

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