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

HRID 969830Notes

Reaction equation

HRID 969830 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-04b9194d79d04aa185b529522bfdc492
Source dataset
uspto-grants-2007_12
Patent number
US07307094B2

Reaction notes

Loading…