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17th July 2017 @ 18:24

Scheme:

Scheme

Compound 

MW(m) 

Mol(Mmol 

Mol(M) 

Mass 

Density 

Volume(mL) 

Equiv  

LDA, 2.0 M in THF/heptane/ethylbenzene 

+ 20 ML dry THF 

 

 

20.78 

2 

 

 

10.4 

1.05 

4-chlorobenzeneacetonitrile 

in 30mL dry THF 

151.59 

19.79 

 

3000 mg 

 

 

1 

Benzoyl chloride 

in 5mL dry THF 

140.566 

19.79 

 

 

1.21 

2.30 

1 

2-(4-chlorophenyl)-3-oxopentanenitrile 

 

207.66 

19.79 

 

1.55g 

1.104 

1.41mL 

1 

Procedure:

6/1/17 – A dry 1-neck 250 mL 24/40 round bottom flask with septum was put under an Argon environment while the 20 mL dry THF was added and 10.4 mL 2.0 M LDA to give a light-med brown-orange solution, which was cooled to ~ -80 ˚C with dry ice/acetone.  A clear, colorless solution of 4-chlorobenzeneacetonitrile in 30 mL dry THF was then added to the solution at about 4 drops/sec down the cooled side of the 250 mL RB flask to give a clear light-med brown-orange solution, which was stirred for approximately 10 minutes at ~ -80 ˚C.  With dry ice/acetone bath still in place, a clear, colorless solution of propionyl chloride in 5 mL dry THF was added dropwise at about ~ 2 drops/second to give a cloudy light-medium tan suspension, which was allowed to stir overnight and warm to room temperature slowly as the cooling bath warmed. 

6/2/17 -  In the morning a light-medium tan suspension was present.  The reaction was quenched at RT with saturated aqueous ammonium chloride which afforded a clear, light-medium red-orange solution with a white/colorless solid in the bottom. 

 The reaction was transferred to a separatory funnel, and the organic layer was washed with H2O (the NH4Cl solid dissolved with addition of H2O), brine, dried over MgSO4, and concentrated to a dark red-brown color.  

To the resulting crude product was added a minimal amount of CH2Cl2, followed by a minimal amount of dry silica.  The volatiles were removed and the dry silica was stored in the fridge overnight.  

The resulting silica was dry transferred onto a silica column. 

The column was eluted with 10:90 EtOAc/Hexanes and 20:80 EtoOAc/Hexanes until the last product began to come off column, followed by EtOAc to completely remove it. Fractions 14-19 showed one of the products with the highly concentrated top spot; Fractions 27-38 showed another product near the bottom of the baseline. 


TLC Results:

  • SM = 4-chlorobenzeneacetonitrile 

  • Cospot 

  • P = Reaction solution post work up.  

  • Spots are UV active.  

  • 10:90 EtOAc in Hexanes  

    JSLT_BenzoylTLC
     
    JSLT_BenzoylTLC
    JSLT_BenzoylTLC
    JSLT_BenzoylTLC


    The starting eluent for column was 30:70 EtOAc:Hexanes. Fractions 63-80 were collected and the solvent was removed under educed pressure.  6/6/17 NMR is still malfunctioning so there is no identification on the multiple products. Products were weighed. 

      • Fractions 14-19: 1.43g 

      • Fractions 27-38: 0.50g 

      • Fractions 63-80: 0.335g

 

6/6/2017 NMR is still malfunctioning so there is no identification on the mutiple products.

6/8/17 NMR for the collected fractions indicated that one of the products was in fractions 14-19 and the other product was in fractions 63-80. Fractions 27-38 appeared to contained starting material (4-chlorobenzeneacetonitrile).

 

JSLT_BEnzoyl4_13.png
JSLT_Benzoyl44_1.png
JS_LTBEnzoyl444_1.png

 

Attached Files
Scheme
JSLT_BenzoylTLC
JSLT_BenzoylTLC
JSLT_BenzoylTLC
JSLT_BenzoylTLC
JSLT_BenzoylTLC
JSLT_BEnzoyl4_13.png
JSLT_Benzoyl44_1.png
JS_LTBEnzoyl444_1.png