P-Xylene → 7-Bromo-2-(3-fluoro-4-methoxyphenyl)-5-methoxy-1,3-benzoxazole

HRID 491729Notes

Reaction equation

HRID 491729 reaction equation
FC1C=C(C=CC=1OC)C(O[C:8]1[C:13]([NH:14][C:15](=[O:25])[C:16]2[CH:21]=[CH:20][C:19]([O:22][CH3:23])=[C:18]([F:24])[CH:17]=2)=[CH:12][C:11]([O:26][CH3:27])=[CH:10][C:9]=1[Br:28])=O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.CC1C=CC(C)=CC=1>O>[Br:28][C:9]1[C:8]2[O:25][C:15]([C:16]3[CH:21]=[CH:20][C:19]([O:22][CH3:23])=[C:18]([F:24])[CH:17]=3)=[N:14][C:13]=2[CH:12]=[C:11]([O:26][CH3:27])[CH:10]=1

Participants

5

Reactant 3

HCID 7809P-XyleneHCID 521998p-Toluenesulfonic acid monohydrateHCID 111799682-Bromo-6-[(3-fluoro-4-methoxybenzoyl)amino]-4-methoxyphenyl 3-fluoro-4-methoxybenzoate

Product 1

HCID 114281017-Bromo-2-(3-fluoro-4-methoxyphenyl)-5-methoxy-1,3-benzoxazoleYield 80.9%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A suspension of 2-bromo-6-[(3-fluoro-4-methoxybenzoyl)amino]-4-methoxyphenyl 3-fluoro-4-methoxybenzoate (46.0 g, 88.1 mmol), p-toluenesulfonic acid monohydrate (33.5 g, 177.2 mmol) and anhydrous p-xylene (1 l) was refluxed for 3 h with continuous water removal (Dean Stark Trap). The initial suspension turned into a brown solution at refluxing temperature. The solids were filtered off and washed with ethyl ether. The solids were suspended in ethyl ether (200 mL), stirred for 10 min, filtered off and dried to give a tan solid (25.1 g, m.p. 175-177° C.). The ethyl ether layer was concentrated to 20 mL and 2.5 g of additional product was obtained (90% overall yield). MS m/e 352 (M+H)+.

Workup

  1. temperatureat refluxing temperature
  2. filtrationThe solids were filtered off
  3. washwashed with ethyl ether
  4. filtrationfiltered off
  5. customdried

Sources & evidence

ORD record
ord-8e7ebf707323456a957abff691523944
Source dataset
uspto-grants-2009_05
Patent number
US07531564B2

Reaction notes

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