p-Toluenesulfonic acid → HCID 66998483, compound

HRID 2064779Notes

Reaction equation

HRID 2064779 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[CH:8][C:9]([Cl:16])=[C:10]2[O:14][CH:13](O)[CH2:12][C:11]=12)=[O:5])[CH3:2].C(OC(C1C=CC(Cl)=C2OC(OC)CC=12)=O)C.CC1C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[CH:8][C:9]([Cl:16])=[C:10]2[O:14][CH:13]=[CH:12][C:11]=12)=[O:5])[CH3:2]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acid2×HCID 66998395HCID 66998395, compoundHCID 66998604HCID 66998604, compound

Product 1

HCID 66998483HCID 66998483, compound

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

A mixture of 7-chloro-2-hydroxy-2,3-dihydro-benzofuran-4-carboxylic acid ethyl ester and 7-chloro-2-methoxy-2,3-dihydro-benzofuran-4-carboxylic acid ethyl ester (3.36 g, see above) in toluene (20 mL) is added dropwise to a solution of PTSA (0.69 mmol) in toluene (14 mL) which is heated to reflux. Heating is continued for 5 h, an additional portion of PTSA (0.69 mmol) is added and the mixture is again heated to reflux for 150 min. The solvents are removed in vacuo and the residue is purified by flash chromatography (gradient: heptane to heptane/EtOAc 95/5) to give the desired product. 1H-NMR (CDCl3): δ=7.95 (d, J=8.3 Hz, 1H); 7.81 (s, 1H); 7.45 (s, 1H); 7.38 (d, J=8.0 Hz, 1H); 4.47 (q, J=7.0 Hz, 2H); 1.48 (t, J=7.0 Hz, 3H).

Workup

  1. temperatureis heated to reflux
  2. temperatureHeating
  3. temperaturethe mixture is again heated
  4. temperatureto reflux for 150 min
  5. customThe solvents are removed in vacuo
  6. customthe residue is purified by flash chromatography (gradient: heptane to heptane/EtOAc 95/5)

Sources & evidence

ORD record
ord-45a2e47c6a72488082209c1a83b19f2d
Source dataset
uspto-grants-2012_10
Patent number
US08288435B2

Reaction notes

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