p-Toluenesulfonic acid → 2-Oxazoleacetic acid, α-[[3-[2-(1,1-dimethylethoxy)-2-oxoethoxy]phenyl]methylene]-4,5-diphenyl-, ethyl ester, (Z)-

HRID 2082083Notes

Reaction equation

HRID 2082083 reaction equation
[C:1]1([C:7]2[N:8]=[C:9]([CH2:18][C:19]([O:21][CH2:22][CH3:23])=[O:20])[O:10][C:11]=2[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.CC([CH:28]([O:32][C:33]1[CH:38]=[CH:37][CH:36]=[C:35]([CH:39]=O)[CH:34]=1)[C:29]([O-:31])=[O:30])(C)C.N1CCCCC1.[C:47]1([CH3:57])[CH:52]=CC(S(O)(=O)=O)=C[CH:48]=1>C(Cl)Cl.C1(C)C=CC=CC=1>[CH3:48][C:47]([CH3:57])([O:31][C:29]([CH2:28][O:32][C:33]1[CH:34]=[C:35](/[CH:39]=[C:18](/[C:9]2[O:10][C:11]([C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=3)=[C:7]([C:1]3[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=3)[N:8]=2)\[C:19]([O:21][CH2:22][CH3:23])=[O:20])[CH:36]=[CH:37][CH:38]=1)=[O:30])[CH3:52]

Participants

7

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 8082PiperidineHCID 14971801HCID 14971801, compoundHCID 86746555HCID 86746555, compound

Product 1

HCID 443507152-Oxazoleacetic acid, α-[[3-[2-(1,1-dimethylethoxy)-2-oxoethoxy]phenyl]methylene]-4,5-diphenyl-, ethyl ester, (Z)-Yield 97%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Procedure

A mixture of ethyl 4,5-diphenyl-2-oxazoleacetate (25.00 g, 81 mmol), 1,1-dimethylethyl(3-formylphenoxy)acetate (19.22 g, 81 mmol), piperidine (0.69 g, 8 mmol), p-toluenesulfonic acid (catalytic quantity) and toluene (200 mL) was heated at reflux under a Dean-Stark trap. After about 18 hours, the mixture was cooled, diluted with CH2Cl2 and washed with water (2×) and saturated NaCl solution before being dried over Mg2SO4. Evaporation of the solvent left an oil which was subjected to chromatography on a column of silica gel. Elution with a mixture of hexanes and ethyl acetate (4:1) afforded the title compound (41.49 g, 97%) as an oil. IR (film) 1760, 1730 (CO2R) cm-1 ; 1H NMR (CDCl3) δ1.28 to 1.36 (4H, overlapping triplets, OCH2CH3), 1.37 and 1.47 (18H, singlets, C(CH3)3), 4.30 and 4.50 (4H, singlets, OCH2CO2tBu), 4.33 (2H, q, J=7Hz, OCH2CH3 of one isomer), 4.41 (2H, q, J=7Hz, OCH2CH3 of other isomer), 6.70 to 7.70 (29H, m, aromatic H+1 olefinic H), 8.07 (1H, s, olefinic H of (E) isomer); MS m/z 526 (MH+).

Workup

  1. temperaturewas heated
  2. temperatureat reflux under a Dean-Stark trap
  3. temperaturethe mixture was cooled
  4. washwashed with water (2×) and saturated NaCl solution
  5. dry with materialbefore being dried over Mg2SO4
  6. customEvaporation of the solvent
  7. waitleft an oil which
  8. washElution
  9. additionwith a mixture of hexanes and ethyl acetate (4:1)

Sources & evidence

ORD record
ord-d5de48abaf314ea99938ec0e1394f68e
Source dataset
uspto-grants-1993_02
Patent number
US05187188

Reaction notes

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