p-Toluenesulfonic acid → HCID 20319637, compound

HRID 2398753Notes

Reaction equation

HRID 2398753 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]([CH3:15])[C:10]([O:12]CC)=[O:11])[CH:5]=[CH:6][C:7]=1[OH:8].[F:16][C:17]1[CH:22]=[CH:21][C:20]([CH2:23][C:24](O)=O)=[CH:19][CH:18]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1.C1(C)C(C)=CC=CC=1>O>[F:16][C:17]1[CH:22]=[CH:21][C:20]([CH2:23][C:24]2[O:8][C:7]3[CH:6]=[CH:5][C:4]([CH:9]([CH3:15])[C:10]([OH:12])=[O:11])=[CH:3][C:2]=3[N:1]=2)=[CH:19][CH:18]=1

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 7237O-XyleneHCID 98372-(4-Fluorophenyl)acetic acidHCID 12202638Ethyl 3-amino-4-hydroxy-phenyl-propionate

Product 1

HCID 20319637HCID 20319637, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of ethyl 3-amino-4-hydroxy-phenyl-propionate (4 g.), 4-fluoro-phenyl-acetic acid (3 g.), p-toluene sulphonic acid (0.1 g.) and xylene (50 ml.) was heated under reflux for 20 hours and the water which formed was removed using a Dean and Stark apparatus. The solution was evaporated to dryness and the residue dissolved in ether. The solution was washed with 2N-sodium hydroxide solution (x2) and water, then stirred with charcoal and anhydrous sodium sulphate, filtered and evaporated to dryness. The residual oil (3.7 g., ND22.5 1.5469) was dissolved in ethanol (30 ml.) and 2N-sodium hydroxide solution (30 ml) was added with stirring over 15 minutes. The reaction mixture was stirred for 21/2 hours during which time water (250 ml) was slowly added. The solution was extracted with ether (x2), acidified with concentrated hydrochloric acid and then extracted with ether (x3). These ethereal extracts were washed with water, dried over anhydrous sodium sulphate and evaporated to give an oil. This oil was purified using prep. tlc plates to give 2-[2-(4-fluorobenzyl)-5-benzoxazolyl]propionic acid as a white solid, mpt 91°-93° C., which was characterised by IR UV and NMR spectroscopy and by microanalysis which gave C 68.40%, H 3.86%, N4.64%; C17H14FNO3 requires C 68.23%, H 4.68%, N 4.68%

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 20 hours
  3. customwas removed
  4. customThe solution was evaporated to dryness
  5. dissolutionthe residue dissolved in ether
  6. washThe solution was washed with 2N-sodium hydroxide solution (x2) and water
  7. filtrationfiltered
  8. customevaporated to dryness
  9. dissolutionThe residual oil (3.7 g., ND22.5 1.5469) was dissolved in ethanol (30 ml.)
  10. addition2N-sodium hydroxide solution (30 ml) was added
  11. stirringwith stirring over 15 minutes
  12. stirringThe reaction mixture was stirred for 21/2 hours during which time water (250 ml)
  13. additionwas slowly added
  14. extractionThe solution was extracted with ether (x2)
  15. extractionextracted with ether (x3)
  16. washThese ethereal extracts were washed with water
  17. dry with materialdried over anhydrous sodium sulphate
  18. customevaporated
  19. customto give an oil
  20. customThis oil was purified

Sources & evidence

ORD record
ord-2e500ac05b5b4c9fa5ef369341f14020
Source dataset
uspto-grants-1977_05
Patent number
US04025637

Reaction notes

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