Reaktion #324406

Reaktionsgleichung

5-[4-(tert-butyldimethylsilyloxy)phenyl]-3-(4-nitrophenyl)pyrazin-2-amine

5-[4-(tert-Butyldimethylsilyloxy)phenyl]-3-(4-nitrophenyl)pyrazin-2-amine

2-[4-(tert-butyldimethylsilyl oxy)phenyl]acetyl chloride

2-[4-(tert-butyldimethylsilyloxy)phenyl]acetyl chloride

water

→

Compound 11o

Ausbeute 48.1%

2-[4-(tert-Butyldimethylsilyloxy)phenyl]-N-[5-{4-(tert-butyldimethylsilyloxy)phenyl}-3-(4-nitrophenyl)pyrazin-2-yl]acetamide

Ausbeute 48.1%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared above at 0° C.
2. 2
   Temperaturthe mixture was heated
3. 3
   TemperaturAfter cooling to room temperature
4. 4
   Extraktionthe product was extracted with ethyl acetate (100 mL×3)
5. 5
   ExtraktionThe combined organic extract
6. 6
   Waschenwas washed successively with water (200 mL) and brine (200 mL)
7. 7
   Trocknenby drying over anhydrous sodium sulfate
8. 8
   FiltrationAfter filtration and concentration under reduced pressure
9. 9
   Sonstigethe residue was purified by column chromatography (silica gel 50 g, n-hexane/ethyl acetate=2/1)

Vorschrift

Under an argon atmosphere, to a mixture of 5-[4-(tert-butyldimethylsilyloxy)phenyl]-3-(4-nitrophenyl)pyrazin-2-amine (7o) (317 mg, 751 μmol) and 4-(dimethylamino)pyridine (15.3 mg, 125 μmol) dissolved in anhydrous pyridine (15 mL) was added 2-[4-(tert-butyldimethylsilyl oxy)phenyl]acetyl chloride (10) prepared above at 0° C. and the mixture was heated with stirring at 50° C. for 20 hours. After cooling to room temperature, to this was added water and the product was extracted with ethyl acetate (100 mL×3). The combined organic extract was washed successively with water (200 mL) and brine (200 mL), followed by drying over anhydrous sodium sulfate. After filtration and concentration under reduced pressure, the residue was purified by column chromatography (silica gel 50 g, n-hexane/ethyl acetate=2/1) to give Compound 11o (242 mg, 361 μmol, 48.1%) as a yellow solid. Rf=0.30 (n-hexane/ethyl acetate=2/1); 1H NMR (400 MHz, DMSO-d6) δ 0.15 (s, 6H), 0.20 (s, 6H), 0.92 (s, 9H), 0.93 (s, 9H), 3.44 (s, 2H), 6.67-6.74 (AA′BB′, 2H), 6.94-7.07 (2AA′BB′, 4H), 7.80-7.86 (AA′BB′, 2H), 8.01-8.12 (2AA′BB′, 4H), 9.05 (s, 1H), 10.85 (s, 1H); 13C NMR (67.8 MHz, DMSO-d6) δ −4.5 (2C), −4.6 (2C), 17.9, 18.0, 25.50 (3C), 25.51 (3C), 41.6, 119.4 (2C), 120.4 (2C), 123.2 (2C), 127.4, 128.2, 128.52 (2C), 128.54 (2C), 130.4 (2C), 138.7, 143.0, 144.5, 145.0, 146.9, 147.9, 153.9, 156.9, 168.9; IR (KBr, cm−1) 700, 741, 781, 839, 914, 1169, 1265, 1348, 1443, 1508, 1603, 1670, 2857, 2930, 2955.

Quelle