Water → 2-Oxazolepropanoic acid, 5-(4-hydroxyphenyl)-4-phenyl-

HRID 542881Notes

Reaction equation

HRID 542881 reaction equation
C[O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[O:13][C:12]([CH2:14][CH2:15][C:16]([OH:18])=[O:17])=[N:11][C:10]=2[C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)=[CH:5][CH:4]=1.B(Br)(Br)Br.O>ClCCl>[OH:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]2[O:13][C:12]([CH2:14][CH2:15][C:16]([OH:18])=[O:17])=[N:11][C:10]=2[C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=2)=[CH:7][CH:8]=1

Participants

5

Reactant 3

HCID 962WaterHCID 25134Boron tribromideHCID 20207520HCID 20207520, compound

Product 1

HCID 113813042-Oxazolepropanoic acid, 5-(4-hydroxyphenyl)-4-phenyl-

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

5-(4-methoxyphenyl)-4-phenyl-2-oxazolepropanoic acid (18.5 g, 0.056 m) dissolved in 700 ml dichloromethane was treated with boron tribromide (275 ml of 1M in dichloromethane) at 25° C. for twenty hours. The solution was poured into 1 l of ice and water and extracted with 2×500 ml of diethyl ether. The organic extracts were washed with water and extracted with 2×500 ml 1N sodium hydroxide. The basic aqueous solution was acidified with 12N hydrochloric acid to pH 2 and extracted with diethyl ether. The ether solution was washed with brine, dried over anhydrous MgSO4 and evaporated. Thin layer chromatography on silica gel 60 with methylisobutylketone:CHCl3 :acetic acid 50:50:1 revealed two products detectable with U.V. and Bray's phenol spray. Comparative TLC demonstrated that the less polar product corresponded to metabolite II and the more polar product corresponded to metabolite III of Janssen et al. The two products were separated by HPLC on silica gel with methylene chloride:ethyl acetate:acetic acid 80:20:1. The appropriate fractions were pooled and evaporated. 9.0 Grams of the title and major product were obtained which were crystallized from 100 ml of hot ethyl acetate by chilling. Yield: 5.1 g, m.p. 175°-176°.

Workup

  1. extractionextracted with 2×500 ml of diethyl ether
  2. washThe organic extracts were washed with water
  3. extractionextracted with 2×500 ml 1N sodium hydroxide
  4. extractionextracted with diethyl ether
  5. washThe ether solution was washed with brine
  6. dry with materialdried over anhydrous MgSO4
  7. customevaporated
  8. customwere separated by HPLC on silica gel with methylene chloride:ethyl acetate:acetic acid 80:20:1
  9. customevaporated
  10. custom9.0 Grams of the title and major product were obtained which
  11. customwere crystallized from 100 ml of hot ethyl acetate
  12. temperatureby chilling

Sources & evidence

ORD record
ord-701f4a89902a433bba352c884b6ec780
Source dataset
uspto-grants-1987_04
Patent number
US04659728

Reaction notes

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