Tetrahydrofuran → 2-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester

HRID 37587

Reaktionsgleichung

Reaktionsgleichung von HRID 37587
F[C:2]1(F)[O:6][C:5]2[CH:7]=CC=CC=2[O:3]1.C([Li])CCC.C[N:18]([CH2:20][CH2:21]N(C)C)C.[O:25]1[CH2:29]C[CH2:27][CH2:26]1>CCCCCC>[CH2:5]([O:6][C:2](=[O:3])[C:21](=[CH:29][O:25][CH2:26][CH3:27])[C:20]#[N:18])[CH3:7]

Komponenten

6

Edukt 4

HCID 8028TetrahydrofuranHCID 8037N,N,N',N'-TetramethylethylenediamineHCID 741032,2-Difluoro-1,3-benzodioxoleHCID 178418339Butyllithium

Produkt 1

HCID 789432-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8058HexaneLösungsmittel

Versuchsvorschrift

7.9 g (50 mmol) of 2,2-difluoro-1,3-benzodioxole are metallated according to Example 2 at -15° C. with 35 ml (55 mmol) of n-butyllithium (1.60M in hexane) and 6.5 g (55 mmol) of TMEDA in 60 ml of hexane. To the 2,2-difluoro-1,3-benzodioxol-4-yllithium which precipitates there is added at -20° C., over a period of 30 minutes, a solution of 9.3 g (55 mmol) of ethoxymethylenecyanoacetic acid ethyl ester in 30 ml of tetrahydrofuran, an orange-red turbid solution being formed during the reaction, which is exothermic. After stirring for 20 minutes at -15° C., the solution is hydrolysed with 50 ml of 2N hydrochloric acid. The aqueous phase is extracted twice with 80 ml of diethyl ether each time. The organic solutions are washed twice with 50 ml of water each time, dried over MgSO4 and concentrated to dryness by evaporation in a vacuum rotary evaporator. The residue is crystallised from ethanol/water 4:1, affording 10.1 g (72%) of colourless platelets of m.p. 87°-88° C.

Aufarbeitung

  1. customTo the 2,2-difluoro-1,3-benzodioxol-4-yllithium which precipitates there
  2. additionis added at -20° C., over a period of 30 minutes

Quellen und Nachweise

ORD-Eintrag
ord-96035804ea854177a51b33bb4396b8b9
Quelldatensatz
uspto-grants-1995_05
Patentnummer
US05420301

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