Pyridine → HCID 14971801, compound

HRID 2082082Notes

Reaction equation

HRID 2082082 reaction equation
C([CH:3](C(Cl)=O)[C:4](Cl)=[O:5])C.[C:10]1([C:16]([CH:18]([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)O)=[O:17])[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.[N:26]1[CH:31]=[CH:30][CH:29]=CC=1.C([O-])(=[O:34])C.[NH4+]>C(Cl)Cl.C(O)(=O)C>[C:20]1([C:18]2[N:26]=[C:31]([CH2:30][C:29]([O:5][CH2:4][CH3:3])=[O:34])[O:17][C:16]=2[C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

7

Reactant 4

HCID 1049PyridineHCID 8400BenzoinHCID 517165Ammonium AcetateHCID 109209242-Ethylpropanedioyl dichloride

Product 1

HCID 14971801HCID 14971801, compoundYield 61.4%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
10 °C

Procedure

Ethyl malonyl chloride (25.68 g, 0.17 mol) was added dropwise to a stirred solution of benzoin (32.90 g, 0.155 mol), pyridine (13.53 g, 0.17 mol) and 4-dimethyl-aminopyridine (catalytic quantity) in CH2Cl2 (300 mL) maintained at about 10° C. with an ice-water bath. The mixture was stirred for about 30 minutes at about 10° C. and about 2 hours at room temperature before being concentrated in vacuo. Glacial acetic acid (600 mL) and ammonium acetate (59.68 g, 0.775 mol) were added to the residue and the mixture heated to reflux. After about 2 hours, the solution was diluted with CH2Cl2, washed with water (3×) and saturated sodium chloride solution and dried over sodium sulfate. Evaporation of the solvent left an oil which was chromatographed on a column of silica gel using a mixture of hexanes and ethyl acetate (17:3) as eluent to give ethyl 4,5-diphenyl-2-oxazoleacetate (29.26 g, 61%). Recrystallization from a mixture of hexanes and CH2Cl2 (8:1) gave pure material, mp 71°-72° C. IR (KBr) 1740 0(CO2Et) cm-1 ; 1H NMR (CDCl3) δ1.26 (3H, t, J=7Hz, CO2CH2CH3), 3.91 (2H, s, CH2CO2Et), 4.22 (2H, q, J=7Hz, OCH2), 7.25 to 7.45 (6H, m, aromatic H), 7.50 to 7.75 (4H, m, aromatic H); MS m/z 308 (MH+).

Workup

  1. concentrationbefore being concentrated in vacuo
  2. temperaturethe mixture heated to reflux
  3. waitAfter about 2 hours
  4. washwashed with water (3×) and saturated sodium chloride solution
  5. dry with materialdried over sodium sulfate
  6. customEvaporation of the solvent
  7. waitleft an oil which
  8. customwas chromatographed on a column of silica gel using
  9. additiona mixture of hexanes and ethyl acetate (17:3) as eluent

Sources & evidence

ORD record
ord-e31468d75a334b349834da4c0d3214a5
Source dataset
uspto-grants-1993_02
Patent number
US05187188

Reaction notes

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