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17th July 2017 @ 19:57

Reaction Scheme:

Screen Shot 2017-07-17 at 2.58.36 PM.png

Reactants and Products

SM/P 

(Trimethylsilyl)diazomethane 

methanol, anhydrous 

2-(4-chlorophenyl)-3-oxobutanenitrile 

(Z)-2-(4-chlorophenyl)-

3-methoxybut-2-enenitrile 

mw 

114.2230 

32.04 

193.63 

207.66 

Equiv 

1.20 

  

1.00 

1.00 

mmol 

7.46 

  

6.21 

6.21 

mg 

  

  

1203 

1290 

mL 

3.73 

28 

  

  

g/mL 

  

0.791 

  

  

M 

2.0 

  

  

  

  

in Et2O 

  

  

  

bp ˚C 

  

64.7 

  

  

Procedure:

7/12/17  To a 1-neck 24/40 x 250 mL RB with stir bar and septum were added 140 mL anhydrous toluene and 28 mL anhydrous methanol with stirring under a balloon of Ar.  To this stirring, clear, colorless solution was added 3.73 mL of a 2.0 M solution of TMS-diazomethane dropwise at about 1 drop/second to give a clear, light yellow/brown solution which was stirred at RT for 5 hours. 

 The Ar balloon was removed, and mineral oil bubbler line was connected via needle through the septum.  A clear, colorless solution in 7 mL of anhydrous methanol was then added dropwise at about 1 drop/second.  N2 gas generation was  evident by bubbling of the bubbler.  

7/13/17 The reaction mixture was diluted with 14 mL Et2O and 70 mL 10% ac AcOH.  The aqueous phase was extracted 3x Et2O, and the combined organic layer was washed with saturated aqueous K2CO3, dried over MgSO4placed on the high vac and concentrated to yield an amber/brown oil (1.41g, 6.79 mmol, 109% yield).  

7/14/17 The crude product was purified by column chromatography, using 30:70 EtOAc: Hexanes as the starting eluent. Fraction 12-26 were collected, and the solvent was removed under reduced pressure to yield an amber/brown-colored oil (0.565 g, 2.72 mmol, 44% yield). 

7/13/2017 TLC Results  

  • SM= 2-(4-chlorophenyl)-3-oxobutanenitrile 

  • Cospot 

  • P= Fractions 12-26 

    Screen Shot 2017-07-17 at 3.05.08 PM.png

7/14/2017 After the column, msot impurities disappeared from the NMR. Only one small impurity( on the left) remained present.

Screen Shot 2017-07-17 at 3.07.56 PM.png


 

Attached Files
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Screen Shot 2017-07-17 at 3.07.56 PM.png