p-Toluenesulfonic acid monohydrate → 2-(3,5-Dimethoxy-4-methylphenyl)-1,3-benzoxazole

HRID 7736

Reaction equation

HRID 7736 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:17]=[C:18]([O:21][CH3:22])[C:19]=1[CH3:20])[C:6]([NH:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1[O:15]C)=O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:22][O:21][C:18]1[CH:17]=[C:5]([C:6]2[O:15][C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=3[N:8]=2)[CH:4]=[C:3]([O:2][CH3:1])[C:19]=1[CH3:20]

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 25993393,5-dimethoxy-N-(2-methoxyphenyl)-4-methylbenzamide

Product 1

HCID 219909742-(3,5-Dimethoxy-4-methylphenyl)-1,3-benzoxazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 3,5-dimethoxy-N-(2-methoxyphenyl)-4-methylbenzamide (1.29 g, 4.49 mmol), toluene (22 mL), p-toluenesulfonic acid monohydrate (5.9 g, 31 mmol) and molecular sieves was refluxed until no starting material was observed by TLC. Cooled mixture to rt and filtered, washing with warm chloroform. Removal of solvent from filtrate afforded a yellow solid. Purification of crude solid by flash chromatography on silica gel using 1:3 EtOAc:hexanes gave the desired intermediate, 2-(3,5-dimethoxy-4-methylphenyl)-1,3-benzoxazole, as a colorless solid.

Workup

  1. temperaturewas refluxed until no starting material
  2. filtrationfiltered
  3. washwashing with warm chloroform
  4. customRemoval of solvent from filtrate
  5. customafforded a yellow solid
  6. customPurification of crude solid by flash chromatography on silica gel using 1:3 EtOAc

Sources & evidence

ORD record
ord-450eaf900c1b41f5a2503bdf4b4d4c54
Source dataset
uspto-grants-2006_08
Patent number
US07087601B2

Linked notes

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