Ethyl Acetate → 6-Bromo-2,3-dihydro-4H-1-benzothiopyran-4-one

HRID 1955552Notes

Reaction equation

HRID 1955552 reaction equation
[Br:1][C:2]1[CH:13]=[CH:12][C:5]([S:6][CH2:7][CH2:8][C:9]([OH:11])=O)=[CH:4][CH:3]=1.CCOC(C)=O>CS(O)(=O)=O.O>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:6][CH2:7][CH2:8][C:9](=[O:11])[C:12]=2[CH:13]=1

Participants

5

Reactant 2

HCID 8857Ethyl AcetateHCID 167762423-(4-Bromothiophenoxy)propionic acid

Product 1

HCID 139537366-Bromo-2,3-dihydro-4H-1-benzothiopyran-4-one

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6395Methanesulfonic AcidSolvent

Procedure

A solution of 3.63 g (13.9 mmol) of 3-(4-bromothiophenoxy)propionic acid in 60 ml methanesulfonic acid was heated to 75° C. for 1.5 hours. After cooling to room temperature the solution was diluted with H2O and extracted with EtOAc. The combined organic layers were washed with 2N aqueous NaOH, H2O, and saturated aqueous NaCl and then dried over MgSO4. Removal of the solvent under reduced pressure afforded a yellow solid from which the product was isolated by column chromatography (3% EtOAc--hexanes) as a pale-yellow solid. 1H NMR (CDCl3): δ 8.22 (1H, d, J=2.1 Hz), 7.48 1H, dd, J=2.1,8.3 Hz), 7.17 (1H, d, J=8.5 Hz), 3.24 (2H, t, J=6.4 Hz), 2.98 (2H, t, J=6.7 Hz).

Workup

  1. extractionextracted with EtOAc
  2. washThe combined organic layers were washed with 2N aqueous NaOH, H2O, and saturated aqueous NaCl
  3. dry with materialdried over MgSO4
  4. customRemoval of the solvent under reduced pressure
  5. customafforded a yellow solid from which the product

Sources & evidence

ORD record
ord-c59ae49e7c9547ecb3dd5ce1334827b5
Source dataset
uspto-grants-1998_07
Patent number
US05776699

Reaction notes

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