Réaction #420784

Équation de réaction

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

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

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

water

→

Compound 11f

Rendement 44.4%

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

Rendement 44.4%

Solvants

pyridine

Conditions de réaction

Traitement

1. 1
   Autreprepared above at 0° C.
2. 2
   Températurethe mixture was heated
3. 3
   TempératureAfter cooling to room temperature
4. 4
   Extractionthe product was extracted with ethyl acetate (200 mL×3)
5. 5
   ExtractionThe combined organic extract
6. 6
   Lavagewas washed successively with water (200 mL) and brine (200 mL)
7. 7
   Séchageby drying over anhydrous sodium sulfate
8. 8
   FiltrationAfter filtration and concentration under reduced pressure
9. 9
   Autrethe residue was purified by column chromatography (silica gel 50 g, n-hexane/ethyl acetate=3/1)
10. 10
    AutreThe resulting solid was recrystallized (n-hexane/ethyl acetate)

Mode opératoire

Under an argon atmosphere, to a mixture of 5-[4-(tert-butyldimethylsilyloxy)phenyl]-3-(thiophen-2-yl)pyrazin-2-amine (7f) (600 mg, 1.59 mmol) and 4-(dimethylamino)pyridine (19.8 mg, 162 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 15 hours. After cooling to room temperature, to this was added water and the product was extracted with ethyl acetate (200 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=3/1). The resulting solid was recrystallized (n-hexane/ethyl acetate) to give Compound 11f (446 mg, 706 μmol, 44.4%) as a colorless solid. Rf=0.26 (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), 0.97 (s, 9H), 3.65 (s, 2H), 0.678-6.86 (AA′BB′, 2H), 6.97-7.06 (m, 3H, includes AA′BB′), 7.19-7.27 (AA′BB′, 2H), 7.51 (dd, 1H, J=0.9, 3.7 Hz), 7.69 (dd, 1H, J=0.9, 5.0 Hz), 8.06-8.14 (AA′BB′, 2H), 8.93 (s, 1H), 10.60 (s, 1H); 13C NMR (75.5 MHz, DMSO-d6) δ −4.6 (4C), 17.9, 18.0, 25.50 (3C), 25.54 (3C), 41.9, 119.6 (2C), 120.4 (2C), 127.8, 127.9, 128.0, 128.2 (2C), 128.4, 129.5, 130.5 (2C), 137.3, 140.5, 140.6, 142.5, 148.0, 153.9, 157.0, 170.3; IR (KBr, cm−1) 419, 519, 673, 704, 741, 781, 802, 839, 916, 1169, 1265, 1335, 1362, 1373, 1414, 1439, 1472, 1510, 1605, 1667, 2857, 2887, 2930, 2955, 3221; HRMS (ESI+) m/z 654.2617 ([M+Na]+, C34H45N3NaO3Si2+ requires 654.2612).

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