P-Xylene → 7-Bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol

HRID 858232Notes

Reaction equation

HRID 858232 reaction equation
COC1C=CC(C(O[C:10]2[C:15]([NH:16][C:17](=[O:26])[C:18]3[CH:23]=[CH:22][C:21]([O:24]C)=[CH:20][CH:19]=3)=[CH:14][C:13]([O:27]C)=[CH:12][C:11]=2[Br:29])=O)=CC=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.CC1C=CC(C)=CC=1>O>[Br:29][C:11]1[C:10]2[O:26][C:17]([C:18]3[CH:23]=[CH:22][C:21]([OH:24])=[CH:20][CH:19]=3)=[N:16][C:15]=2[CH:14]=[C:13]([OH:27])[CH:12]=1

Participants

5

Reactant 3

HCID 7809P-XyleneHCID 521998p-Toluenesulfonic acid monohydrateHCID 12148968HCID 12148968, compound

Product 1

HCID 1354183737-Bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-olYield 88.9%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A suspension of 2-bromo-4-methoxy-6-[(4-methoxybenzoyl)amino]phenyl 4-methoxybenzoate (42.0 g, 86.4 mmol), p-toluenesulfonic acid monohydrate (32.8 g, 172.8 mmol) and anhydrous p-xylene (800 mL) was refluxed for 1 h with continuous water removal (Dean-Stark Trap). The initial suspension turned into a brown solution at refluxing temperature. The mixture was cooled to room temperature and washed with NaOH (2N). The organic layer was dried over MgSO4. Evaporation and crystallization from acetone/ethyl ether gave an off-white solid (23.5 g, 82% yield, m.p. 139–141° C.); MS m/e 334 (M+H)+.

Workup

  1. temperatureat refluxing temperature
  2. washwashed with NaOH (2N)
  3. dry with materialThe organic layer was dried over MgSO4
  4. customEvaporation and crystallization from acetone/ethyl ether

Sources & evidence

ORD record
ord-79b0475afbc547d09efe72a6f2173925
Source dataset
uspto-grants-2006_12
Patent number
US07148247B2

Reaction notes

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