Pyridine → Toluene-4-sulfonic acid 6-chloro-2-oxo-2H-1-benzopyran-4-yl ester

HRID 495149Notes

Reaction equation

HRID 495149 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7](=[O:12])[CH:6]=[C:5]2[OH:13].N1C=CC=CC=1.[C:20]1([CH3:30])[CH:25]=[CH:24][C:23]([S:26](Cl)(=[O:28])=[O:27])=[CH:22][CH:21]=1>C(Cl)Cl>[Cl:1][C:2]1[CH:11]=[CH:10][C:9]2[O:8][C:7](=[O:12])[CH:6]=[C:5]([O:13][S:26]([C:23]3[CH:24]=[CH:25][C:20]([CH3:30])=[CH:21][CH:22]=3)(=[O:28])=[O:27])[C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 1049PyridineHCID 73974-Toluenesulfonyl chlorideHCID 546863486-Chloro-4-hydroxycoumarin

Product 1

HCID 46179801Toluene-4-sulfonic acid 6-chloro-2-oxo-2H-1-benzopyran-4-yl esterYield 90%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

6-Chloro-4-hydroxycoumarin (25.4 mmol, 5.0 g) is suspended in DCM (50 mL) and pyridine (63.3 mmol, 5.1 mL) is added. The mixture is cooled in an ice bath and p-toluenesulfonyl chloride (26.8 mmol, 5.1 g) is added. The ice bath is removed and the compound slowly dissolves and a solid is deposited (pyridine HCl). After 1 hr the mixture is transferred to a separatory funnel, HCl (2 M) is added, and a solid is formed. The organic layer is removed and the solid-containing aqueous layer is filtered to remove the precipitate. The filtrate is washed with DCM and the combined organic layers are washed with H2O, NaHCO3 (sat.), H2O, and brine. The extract is then dried over MgSO4 and is evaporated. The residue is triturated with Et2O to give the title compound (8.0 g, 90%) as a cream solid. 1H NMR (CDCl3, 400 MHz) δ 7.91 (2H, d, J=8 Hz), 7.54 (1H, d, J=2 Hz), 7.51 (1H, dd, J=2, 9 Hz), 7.42 (2H, d, J=8 Hz), 7.26 (1H, d, J=9 Hz), 6.38 (1H, s), 2.49 (3H, s); LCMS (MeCN—H2O, Luna 3μC18(2) 30×4.6 mm; MS (ESI, Pos.) calcd for C16H11ClO5S m/z [M+H]=351 found [no mass ion detected].

Workup

  1. temperatureThe mixture is cooled in an ice bath
  2. customThe ice bath is removed
  3. dissolutionthe compound slowly dissolves
  4. additionHCl (2 M) is added
  5. customa solid is formed
  6. customThe organic layer is removed
  7. filtrationthe solid-containing aqueous layer is filtered
  8. customto remove the precipitate
  9. washThe filtrate is washed with DCM
  10. washthe combined organic layers are washed with H2O, NaHCO3 (sat.), H2O, and brine
  11. dry with materialThe extract is then dried over MgSO4
  12. customis evaporated
  13. customThe residue is triturated with Et2O

Sources & evidence

ORD record
ord-119b9690803a4d869af22da53c819932
Source dataset
uspto-grants-2009_05
Patent number
US07538233B2

Reaction notes

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