Reaktion #11526

Reaktionsgleichung

methyl thiophen-2,5-dicarboxylate

thionylchloride

(S)-1-(p-tolyl)ethylamine

triethylamin

→

(S)-5-(1-p-Tolyl-ethylcarbamoyl)-thiophene-2-carboxylic acid methyl ester

Ausbeute 71.0%

Lösungsmittel

CH2Cl2

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent and excess of thionylchloride are evaporated under reduced pressure
2. 2
   workup.DISSOLUTIONthe residue is dissolved in CH2Cl2 (10 ml)
3. 3
   SonstigeThe product is isolated
4. 4
   Sonstigeafter acidic work-up and recrystallisation as yellow solid (mp=165° C.) in 71% yield (1.6 g)

Vorschrift

A solution of 1.4 g (7.5 mmol) of methyl thiophen-2,5-dicarboxylate in CH2Cl2 (5 ml) is treated with 1.5 ml (18 mmol) thionylchloride and one drop of DMF and subsequently heated at 80° C. for 1 hour. The solvent and excess of thionylchloride are evaporated under reduced pressure, and the residue is dissolved in CH2Cl2 (10 ml) and treated slowly with (S)-1-(p-tolyl)ethylamine (1.0 g, 7.4 mmol) in CH2Cl2 (10 ml) and triethylamin (2 ml, 14.2 mmol). Stirring at rt is continued for 1 additional hour. The product is isolated after acidic work-up and recrystallisation as yellow solid (mp=165° C.) in 71% yield (1.6 g).

Quelle