Sulfuric Acid → 2-Hydroxyimino-4-p-tolyl-but-3-enenitrile

HRID 48128

Reaktionsgleichung

Reaktionsgleichung von HRID 48128
[C:1]1([CH3:12])[CH:6]=[CH:5][C:4]([CH:7]=[CH:8][CH2:9][C:10]#[N:11])=[CH:3][CH:2]=1.[OH-].[Na+].[N:15](OC)=[O:16].OS(O)(=O)=O.N([O-])=O.[Na+]>CO.CO.O.O>[OH:16][N:15]=[C:9]([CH:8]=[CH:7][C:4]1[CH:3]=[CH:2][C:1]([CH3:12])=[CH:6][CH:5]=1)[C:10]#[N:11]

Komponenten

9

Edukt 5

HCID 1118Sulfuric AcidHCID 12231Methyl nitriteHCID 14798Sodium HydroxideHCID 23668193Sodium NitriteHCID 571191444-(4-Methylphenyl)but-3-enenitrile

Produkt 1

HCID 867593572-Hydroxyimino-4-p-tolyl-but-3-enenitrileAusbeute 76 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 887MethanolLösungsmittelHCID 962WaterLösungsmittelHCID 22242641Methanol--water (1/1)Lösungsmittel

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

In a 3-necked 50 ml flask fitted with a sintered glass gas inlet tube, 2.13 g (0.0135 mol) of 4-p-tolyl-but-3-enenitrile are dissolved in 30 ml of methanol, and cooled to 0° C. Sodium hydroxide (0.54 g; 0.0135 mol) is added. The turbid, slightly brownish mixture is then treated with ca. 0.025 mol of gaseous methyl nitrite bubbled below the surface of the mixture through the gas inlet tube (methyl nitrite is generated by dropwise addition of [0.8 ml of H2SO4 conc+1.6 ml H2O] to a suspension of sodium nitrite (1.72 g; 0.025 mol) in 3 ml of methanol:water 1:1 (v:v); see M. Itoh et al. Org. Synth. Coll vol. VI, 1988, 199). The mixture is then stirred overnight, allowing the temperature to rise to 25° C. The solvent is evaporated in vacuo, the residue is redissolved in water and extracted with toluene. The aqueous phase is then acidified with conc. HCl to pH ca 2, the beige precipitate is filtered, rinsed neutral with water, and dried under vacuum. The crude product is redissolved in ethyl acetate, filtered through a short pad of SiO2, and evaporated. 2-Hydroxyimino-4-p-tolyl-but-3-enenitrile (1.9 g; 76%), mp 135-137° C. is obtained and used without further purification.

Aufarbeitung

  1. customIn a 3-necked 50 ml flask fitted with a sintered glass gas inlet tube
  2. custombubbled below the surface of the mixture through the gas inlet tube (methyl nitrite
  3. customto rise to 25° C
  4. customThe solvent is evaporated in vacuo
  5. dissolutionthe residue is redissolved in water
  6. extractionextracted with toluene
  7. filtrationthe beige precipitate is filtered
  8. washrinsed neutral with water
  9. customdried under vacuum
  10. dissolutionThe crude product is redissolved in ethyl acetate
  11. filtrationfiltered through a short pad of SiO2
  12. customevaporated

Quellen und Nachweise

ORD-Eintrag
ord-d0543945a5a8420b92d3a782a42edabb
Quelldatensatz
uspto-grants-2004_03
Patentnummer
US06703182B1

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