p-Toluenesulfonic acid → 2-(4-Fluorophenyl)benzoxazole

HRID 59637

Reaction equation

HRID 59637 reaction equation
C1(C)C=CC(S(O)(=O)=O)=CC=1.[F:12][C:13]1[CH:28]=[CH:27][C:16]([C:17]([NH:19][C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][C:21]=2[OH:26])=O)=[CH:15][CH:14]=1>>[F:12][C:13]1[CH:28]=[CH:27][C:16]([C:17]2[O:26][C:21]3[CH:22]=[CH:23][CH:24]=[CH:25][C:20]=3[N:19]=2)=[CH:15][CH:14]=1

Participants

3

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 5793834-Fluoro-N-(2-hydroxyphenyl)benzamide2×

Product 1

HCID 29536232-(4-Fluorophenyl)benzoxazole

Conditions

Temperature
110 °C

Procedure

After the flask containing 4-Fluoro-N-(2-hydroxyphenyl)-benzamide in 250 ml of toluene of step 1 was equipped with a Dean-Stark apparatus, p-toluenesulfonic acid (12.2 g, 64 mmol, 0.2 eq) was added. The mixture was stirred at 110° C. for 8 hours. Then heating was stopped and the solution was subsequently washed with 100 ml of water, 2*100 ml of (0.2M) NaOH solution and 100 ml of water. Toluene was removed via rotary evaporator yielding 64 g (94%) of slightly off white 2-(4-fluorophenyl)-1,3-benzoxazole.

Workup

  1. additionwas added
  2. temperatureThen heating
  3. washthe solution was subsequently washed with 100 ml of water, 2*100 ml of (0.2M) NaOH solution and 100 ml of water
  4. customToluene was removed via rotary evaporator

Sources & evidence

ORD record
ord-f89ceeca103e4eb7964c7864d86eeaec
Source dataset
uspto-grants-2016_09
Patent number
US09440935B2

Linked notes

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