Water → (E)-2-[4-(tert-Butyldimethylsilyloxy)phenyl]-N-[5-{4-(tert-butyldimethylsilyloxy)phenyl}-3-styrylpyrazin-2-yl]acetamide

HRID 237198Notes

Reaction equation

HRID 237198 reaction equation
[Si:1]([O:8][C:9]1[CH:14]=[CH:13][C:12]([C:15]2[N:16]=[C:17](/[CH:22]=[CH:23]/[C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=3)[C:18]([NH2:21])=[N:19][CH:20]=2)=[CH:11][CH:10]=1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[Si:30]([O:37][C:38]1[CH:43]=[CH:42][C:41]([CH2:44][C:45](Cl)=[O:46])=[CH:40][CH:39]=1)([C:33]([CH3:36])([CH3:35])[CH3:34])([CH3:32])[CH3:31].O>CN(C)C1C=CN=CC=1.N1C=CC=CC=1>[Si:30]([O:37][C:38]1[CH:39]=[CH:40][C:41]([CH2:44][C:45]([NH:21][C:18]2[C:17](/[CH:22]=[CH:23]/[C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=3)=[N:16][C:15]([C:12]3[CH:11]=[CH:10][C:9]([O:8][Si:1]([C:4]([CH3:7])([CH3:5])[CH3:6])([CH3:2])[CH3:3])=[CH:14][CH:13]=3)=[CH:20][N:19]=2)=[O:46])=[CH:42][CH:43]=1)([C:33]([CH3:36])([CH3:35])[CH3:34])([CH3:32])[CH3:31]

Participants

6

Reactant 3

HCID 962WaterHCID 121887072-[4-(Tert-butyldimethylsilyloxy)phenyl]acetyl chlorideHCID 57516675(E)-5-[4-(tert-Butyldimethylsilyloxy)phenyl]-3-styrylpyrazin-2-amine

Product 1

HCID 67432201(E)-2-[4-(tert-Butyldimethylsilyloxy)phenyl]-N-[5-{4-(tert-butyldimethylsilyloxy)phenyl}-3-styrylpyrazin-2-yl]acetamideYield 69.7%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 1049PyridineSolvent

Conditions

Temperature
50 °C

Procedure

Under an argon atmosphere, to a mixture of (E)-5-[4-(tert-butyldimethylsilyloxy)phenyl]-3-styrylpyrazin-2-amine (7b) (500 mg, 1.24 mmol) and 4-(dimethylamino)pyridine (15.3 mg, 125 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 (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=3/1) to give Compound 11b (563 mg, 864 μmol, 69.7%) as a yellow solid. Rf=0.29 (n-hexane/ethyl acetate=3/1); 1H NMR (400 MHz, DMSO-d6) δ 0.17 (s, 6H), 0.24 (s, 6H), 0.96 (s, 9H), 0.97 (s, 9H), 3.66 (s, 2H), 6.81-6.91 (m, 3H, includes AA′BB′), 6.99-7.04 (AA′BB′, 2H), 7.28-7.40 (m, 7H, includes AA′BB′), 7.82 (d, 1H, J=16 Hz), 8.11-8.19 (AA′BB′, 2H), 8.91 (s, 1H), 10.66 (s, 1H); 13C NMR (75.5 MHz, DMSO-d6) δ −4.5 (2C), −4.6 (2C), 17.8, 17.9, 25.5 (6C), 42.0, 119.7 (2C), 120.3 (2C), 122.5, 127.1 (2C), 128.2 (2C), 128.5, 128.7 (2C), 128.9, 129.0, 130.3 (2C), 133.8, 136.0, 137.8, 142.8, 143.9, 148.0, 154.0, 156.7, 170.6; IR (KBr, cm−1) 471, 521, 638, 691, 746, 781, 806, 839, 914, 968, 1007, 1080, 1103, 1169, 1263, 1325, 1371, 1391, 1414, 1439, 1472, 1510, 1566, 1605, 1659, 2857, 2886, 2930, 2055, 3028, 3057, 3217; HRMS (ESI+) m/z 674.3203 ([M+Na]+, C28H49N3NaO3Si2+ requires 674.3205).

Workup

  1. customprepared above at 0° C.
  2. temperaturethe mixture was heated
  3. temperatureAfter cooling to room temperature
  4. extractionthe product was extracted with ethyl acetate (100 mL×3)
  5. extractionThe combined organic extract
  6. washwas washed successively with water (200 mL) and brine (200 mL)
  7. dry with materialby drying over anhydrous sodium sulfate
  8. filtrationAfter filtration and concentration under reduced pressure
  9. customthe residue was purified by column chromatography (silica gel 50 g, n-hexane/ethyl acetate=3/1)

Sources & evidence

ORD record
ord-52ab64b400c44312b55b6d5b4da09904
Source dataset
uspto-grants-2014_02
Patent number
US08642281B2

Reaction notes

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