Carbon Dioxide → ortho-aminophenylbenzoxazole

HRID 909249Notes

Reaction equation

HRID 909249 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[OH:8].[C:9]12[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=1)[NH:14]C(=O)O[C:10]2=O.C(=O)=O.[OH-].[Na+]>O>[O:8]1[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[N:1]=[C:10]1[C:9]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[NH2:14]

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 58012-AminophenolHCID 8359Isatoic AnhydrideHCID 14798Sodium Hydroxide

Product 1

HCID 4602658ortho-aminophenylbenzoxazole

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

An intimate mixture of 2-aminophenol (109.13 g) and isatoic anhydride (203.9 g) was heated at 140° C. for 2 to 4 h until the formation of carbon dioxide ceased. Then the mixture was placed under vacuum (at a constant pressure of 50 mmHg) and the heating was continued at 180° C. for 3 to 4 h until the formation of water ceased. The melt was poured into a porcellanic mortar and, after cooling, the cold material was pestled, then boiled in a solution of caustic soda (12 g) in water (3.5 L) for 2 to 3 h. After cooling, the precipitate was isolated by filtration, and washed with cold water until the pale blue fluorescence disappeared in the washings. The precipitate was dried at 80° C. to afford 2-(benzo[d]oxazol-2-yl)phenylamine (180 to 185 g). The product was used without further purification in the next stage of preparation.

Workup

  1. additionThe melt was poured into a porcellanic mortar
  2. temperatureafter cooling
  3. temperatureAfter cooling
  4. customthe precipitate was isolated by filtration
  5. washwashed with cold water until the pale blue fluorescence
  6. customThe precipitate was dried at 80° C.

Sources & evidence

ORD record
ord-b7463df4ad564724bf00bf05956e5f9b
Source dataset
uspto-grants-2011_09
Patent number
US08017769B2

Reaction notes

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