3-Hydroxyanthranilic Acid → Methyl 2-(4-fluorophenyl)benzoxazole-4-carboxylate

HRID 506243Notes

Reaction equation

HRID 506243 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=[O:6])[C:3]=1[NH2:11].[F:12][C:13]1[CH:21]=[CH:20][C:16]([C:17](Cl)=[O:18])=[CH:15][CH:14]=1.C(Cl)(=O)C(Cl)=O.CN([CH:31]=[O:32])C>C(Cl)Cl>[F:12][C:13]1[CH:21]=[CH:20][C:16]([C:17]2[O:1][C:2]3[C:3](=[C:4]([C:5]([OH:7])=[O:6])[CH:8]=[CH:9][CH:10]=3)[N:11]=2)=[CH:15][CH:14]=1.[F:12][C:13]1[CH:21]=[CH:20][C:16]([C:17]2[O:18][C:2]3[C:3](=[C:4]([C:5]([O:32][CH3:31])=[O:6])[CH:8]=[CH:9][CH:10]=3)[N:11]=2)=[CH:15][CH:14]=1

Participants

7

Reactant 4

HCID 863-Hydroxyanthranilic AcidHCID 6228DimethylformamideHCID 65578Oxalyl chlorideHCID 678794-Fluorobenzoyl chloride

Product 2

HCID 59626027Methyl 2-(4-fluorophenyl)benzoxazole-4-carboxylateYield 26%HCID 59626030HCID 59626030, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

2-(4-fluorophenyl)benzoxazole-4-carboxylic acid was prepared from 3-hydroxyanthranilic acid and 4-fluorobenzoyl chloride as described in Step A of Example 1. The crude product was dissolved in methylene chloride (20 mL) and the resulting solution treated with oxalyl chloride (1 mL) and DMF (0.05 mL). After stirring at room temperature for 6 h, the reaction was quenched by the addition of methanol (10 mL) and stirred at room temperature for a further 71 h. The reaction was then re-concentrated and the resulting solid purified by column chromatography to afford a 26% yield of methyl 2-(4-fluorophenyl)benzoxazole-4-carboxylate as a white solid: 1H NMR (500 MHz, CDCl3) δ 8.36 (dd, J=14.7, 11.8 Hz, 2H), 8.03 (d, J=14.7 Hz, 1H), 7.78 (d, J=15.2 Hz, 1H), 7.42 (t, J=13.2 Hz, 1H), 7.18 (m, 2H), 4.06 (m, 3H).

Workup

  1. customthe reaction was quenched by the addition of methanol (10 mL)
  2. stirringstirred at room temperature for a further 71 h
  3. concentrationThe reaction was then re-concentrated
  4. customthe resulting solid purified by column chromatography

Sources & evidence

ORD record
ord-72214cb3875c45c395da1366f10bffc0
Source dataset
uspto-grants-2010_08
Patent number
US07781430B2

Reaction notes

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