p-Toluenesulfonic acid monohydrate → 2-(4-Hydroxyphenyl)-5-octylbenzoxazole

HRID 1108926Notes

Reaction equation

HRID 1108926 reaction equation
C([O:4][C:5]1[CH:28]=[CH:27][C:8]([C:9]([NH:11][C:12]2[CH:17]=[C:16]([CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH3:25])[CH:15]=[CH:14][C:13]=2[OH:26])=O)=[CH:7][CH:6]=1)(=O)C.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClC1C=CC=CC=1Cl>[OH:4][C:5]1[CH:28]=[CH:27][C:8]([C:9]2[O:26][C:13]3[CH:14]=[CH:15][C:16]([CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH3:25])=[CH:17][C:12]=3[N:11]=2)=[CH:7][CH:6]=1

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 190211552-(4-Acetoxybenzoylamino)-4-octylphenol

Product 1

HCID 1357951722-(4-Hydroxyphenyl)-5-octylbenzoxazoleYield 80%

Reagents, catalysts & solvents 1

HCID 72391,2-DichlorobenzeneSolvent

Procedure

In a 200 ml-round-bottomed flask, 4.00 g (10.4 mM) of 2-(4-acetoxybenzoylamino)-4-octylphenol, 0.40 g of p-toluenesulfonic acid monohydrate and 40 ml of o-dichlorobenzene were placed, followed by stirring for 1 hour at 188°-192° C. After the reaction, odichlorobenzene in the reaction mixture was distilled off under reduced pressure. To the residue, 1.98 g (30.0 mM) of potassium hydroxide and 60 ml of ethanol was added and stirred for 1 hour on a water bath kept at about 75° C. After the reaction, ethanol in the reaction mixture was distilled off under reduced pressure. Water was added to the resultant residue, followed by addition of 6.0 ml (34.0 mM) of concentrated hydrochloric acid under stirring on an ice bath to precipitate a crystal. The crystal was recovered by filtration and washed with water, followed by recrystallization from ethanol to obtain 2.70 g of 2-(4-hydroxyphenyl)-5-octylbenzoxazole (Yield: 80.0%).

Workup

  1. customAfter the reaction, odichlorobenzene in the reaction mixture
  2. distillationwas distilled off under reduced pressure
  3. additionTo the residue, 1.98 g (30.0 mM) of potassium hydroxide and 60 ml of ethanol was added
  4. stirringstirred for 1 hour on a water bath
  5. customkept at about 75° C
  6. customAfter the reaction, ethanol in the reaction mixture
  7. distillationwas distilled off under reduced pressure
  8. additionWater was added to the resultant residue
  9. additionfollowed by addition of 6.0 ml (34.0 mM) of concentrated hydrochloric acid
  10. stirringunder stirring on an ice bath
  11. customto precipitate a crystal
  12. filtrationThe crystal was recovered by filtration
  13. washwashed with water
  14. customfollowed by recrystallization from ethanol

Sources & evidence

ORD record
ord-beb55715e70f4b0ea3d8f3693c8c0c2b
Source dataset
uspto-grants-1994_06
Patent number
US05318720

Reaction notes

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