Reaktion #420774

Reaktionsgleichung

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

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

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

water

→

Compound 11a

Ausbeute 75.4%

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

Ausbeute 75.4%

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=4/1)

Vorschrift

Under an argon atmosphere, to a mixture of 5-[4-(tert-butyldimethylsilyloxy)phenyl]-3-phenylpyrazin-2-amine (7a) (504 mg, 1.33 mmol) and 4-(dimethylamino)pyridine (16.3 mg, 133 μmol) dissolved in anhydrous pyridine (20 mL) was added 2-[4-(tert-butyldimethylsilyloxy)phenyl]acetyl chloride (10) prepared above at 0° C. and the mixture was heated with stirring at 50° C. for 18 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=4/1) to give Compound 11a (630 mg, 1.01 mmol, 75.4%) as a yellow foamy solid. Rf=0.33 (n-hexane/diethyl ether=2/3); 1H NMR (400 MHz, DMSO-d6) δ 0.18 (s, 6H), 0.23 (s, 6H), 0.94 (s, 9H), 0.96 (s, 9H), 3.47 (s, 2H), 6.72-6.79 (AA′BB′, 2H), 6.96-7.02 (AA′BB′, 2H), 7.03-7.09 (AA′BB′, 2H), 7.29-7.39 (m, 3H), 7.66-7.74 (m, 2H), 8.05-8.12 (AA′BB′, 2H), 8.98 (s, 1H), 10.54 (s, 1H); 13C NMR (75.5 MHz, DMSO-d6) δ −4.6 (4C), 17.9, 18.0, 25.50 (3C), 25.54 (3C), 41.7, 119.5 (2C), 120.3 (2C), 127.8 (2C), 127.9, 128.0 (2C), 128.2 (2C), 128.5, 128.9, 130.3 (2C), 130.5, 137.6, 142.8, 147.6, 148.0, 153.8, 156.7, 169.3; IR (KBr, cm−1) 523, 694, 781, 804, 839, 914, 1020, 1070, 1086, 1105, 1169, 1263, 1371, 1416, 1510, 1605, 1672, 2857, 2886, 2930, 2955, 3040, 3059, 3233; HRMS (ESI+) m/z 648.3043 ([M+Na]+, C36H47N3NaO3Si2+ requires 648.3048).

Quelle