P-Toluic Acid → Methyl 2-p-tolylbenzo[d]oxazole-7-carboxylate

HRID 415202Notes

Reaction equation

HRID 415202 reaction equation
[NH2:1][C:2]1[C:3]([OH:12])=[C:4]([CH:9]=[CH:10][CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].[CH3:13][C:14]1[CH:22]=[CH:21][C:17]([C:18](O)=O)=[CH:16][CH:15]=1>O>[C:14]1([CH3:13])[CH:22]=[CH:21][C:17]([C:18]2[O:12][C:3]3[C:4]([C:5]([O:7][CH3:8])=[O:6])=[CH:9][CH:10]=[CH:11][C:2]=3[N:1]=2)=[CH:16][CH:15]=1

Participants

4

Reactant 2

HCID 7470P-Toluic AcidHCID 12782444Methyl 3-amino-2-hydroxybenzoate

Product 1

HCID 66621103Methyl 2-p-tolylbenzo[d]oxazole-7-carboxylateYield 30.2%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
180 °C

Procedure

Methyl 3-amino-2-hydroxybenzoate (4.4 g, 26 mmol) and 4-methylbenzoic acid (3.6 g, 26.0 mmol) were added to the polyphosphoric acid (20 g). The mixture was heated at 180° C. for 2 hr, and then cooled, poured into water, extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, brine, dried over anhydrous sodium sulfate and condensed to obtain methyl 2-p-tolylbenzo[d]oxazole-7-carboxylate as a white solid (2.1 g, yield 30%). LC-MS (ESI) m/z 268 [M+1]+.

Workup

  1. temperaturecooled
  2. extractionextracted with ethyl acetate
  3. washwashed with saturated sodium bicarbonate solution, brine
  4. dry with materialdried over anhydrous sodium sulfate and condensed

Sources & evidence

ORD record
ord-20307787431a401fb437264867da5ff1
Source dataset
uspto-grants-2012_01
Patent number
US08088760B2

Reaction notes

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