Reaktion #160404

Reaktionsgleichung

sodium bicarbonate

3-[(4-Methyl-cyclohexanecarbonyl)-(4-oxo-cyclohexyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester

dibromoethane

→

3-[(4-Methyl-cyclohexanecarbonyl)-(4-methylene-cyclohexyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester

Ausbeute 81.0%

Lösungsmittel

dichloromethane

tetrahydrofuran

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   workup.STIRRINGwas stirred for two days at this temperature
3. 3
   workup.STIRRINGthe resulting mixture was stirred 3 h at room temperature
4. 4
   Sonstigereaction mixture
5. 5
   Extraktionwas extracted with dichloromethane (3×30 mL)
6. 6
   Trocknendried over sodium sulfate
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe crude was purified by chromatography (30% ethyl acetate/hexanes)

Vorschrift

To a suspension of zinc dust (2.87 g, 44.0 mmol) and dibromoethane (1.00 mL, 14.4 mmol) in tetrahydrofuran (20 mL) stirred under a nitrogen atmosphere at −40° C. was added titane tetrachloride (10 mL of a solution 1M in dichloromethane, 10 mmol). The mixture was then allowed to warm to room temperature and was stirred for two days at this temperature. This methylation reagent (2.5 eq) was added to a solution of 3-[(4-Methyl-cyclohexanecarbonyl)-(4-oxo-cyclohexyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester (0.200 g, 0.440 mmol, 1 eq) in dichloromethane (2 mL) and the resulting mixture was stirred 3 h at room temperature. A saturated solution of sodium bicarbonate was then added and reaction mixture was extracted with dichloromethane (3×30 mL). Organic phases were combined, dried over sodium sulfate and concentrated. The crude was purified by chromatography (30% ethyl acetate/hexanes) to give 160 mg (81%) of 3-[(4-Methyl-cyclohexanecarbonyl)-(4-methylene-cyclohexyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester as a white solid. NMR 1H (CDCl3, 400 MHz): 7.63 ppm (d, 2H); 7.40 ppm (m, 3H); 6.98 ppm (s, 1H); 4.82 ppm (tt, 1H); 4.78 ppm (d, 2H); 3.85 ppm (s, 3H); 2.20 ppm (m, 4H); 2.05 ppm (m, 2H); 1.90 ppm (d, 1H); 1.65 ppm (m, 4H); 1.42 ppm (m, 1H); 1.30 ppm (m, 2H); 1.00 ppm (m, 2H); 0.78 ppm (d, 3H); 0.64 ppm (m, 2H).

Quelle