Pyridine → HCID 69834954, compound

HRID 849852Notes

Reaction equation

HRID 849852 reaction equation
[C:1]([O:5][C:6]([CH2:8][NH:9][C@H:10]([CH2:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1)[C:11]([NH:13][NH:14][C:15]([C:17]([O:19][CH2:20][CH3:21])=[O:18])=[O:16])=O)=[O:7])([CH3:4])([CH3:3])[CH3:2].N1C=CC=CC=1.S(Cl)(Cl)=O>CCOCC.C1COCC1>[CH2:20]([O:19][C:17]([C:15]1[O:16][C:11]([C@H:10]([NH:9][CH2:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[CH2:22][C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)=[N:13][N:14]=1)=[O:18])[CH3:21]

Participants

6

Reactant 3

HCID 1049PyridineHCID 24386Thionyl ChlorideHCID 69835225HCID 69835225, compound

Product 1

HCID 69834954HCID 69834954, compoundYield 54.1%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

1-((2R)-2-((tert-Butoxycarbonyl)methylamino)-3-phenylpropionyl)-2-ethoxycarbonylformylhydrazine (1.4 g, 3.55 mmol) was dissolved in ether (25 ml) and THF (10 ml). Pyridine (1.44 ml 17.75 mmol) was added, and the solution was cooled to 0° C. Thionyl chloride (0.3 ml, 3.90 mmol) was added dropwise. The reaction mixture was stirred at 0° C. for 2 h. The precipitation was filtered off. The solvent was removed in vacuo without warming. The residue was dissolved in toluene (25 ml) and the solution was warmed to reflux for 2 h. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (70 g) with ethyl acetate/dichloromethane 1:2 to give 721 mg of 5-((1R)-1-((tert-butoxycarbonyl)methylamino)-2-phenylethyl)-[1,3,4]oxadiazole-2-carboxylic acid ethylester.

Workup

  1. customThe precipitation
  2. filtrationwas filtered off
  3. customThe solvent was removed in vacuo
  4. temperaturewithout warming
  5. dissolutionThe residue was dissolved in toluene (25 ml)
  6. temperaturethe solution was warmed
  7. temperatureto reflux for 2 h
  8. customThe solvent was removed in vacuo
  9. customThe crude product was purified by flash chromatography on silica (70 g) with ethyl acetate/dichloromethane 1:2

Sources & evidence

ORD record
ord-c71098dd48e04dfd9dc4995044c4fc47
Source dataset
uspto-grants-2000_01
Patent number
US06013658

Reaction notes

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