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18th January 2017 @ 19:31

SNAr mechanism for [NA-02-01].png

 

Reagents

Equivalents

Quantity
 (mg / mL)

mmol

Molecular Weight g/mol

2-Fluorobenzaldehyde

1

250 mg
0.21 mL

2.00 mmol

124.114

Pyrrolidine

1.1

156 mg
0.18 mL

2.20 mmol

71.123

K2CO3

1.1

300 mg

2.20 mmol

138.205

DMF

-

2 mL

 

 

Procedure


Part 1: crude product

2-fluorobenzaldehyde (250 mg, 2.00 mmol) and Pyrrolidine (156 mg, 2.20 mmol) were added to a stirred solution of K2CO3 (300 mg, 2.20 mmol) in 2 mL of DMF and left in a RBF for a week.

After this time a miniwork up and TLC analysis were done (50% EtOAc/pet. Ether) the plate was coated with KMnO4. The solution was diluted in diethyl ether (10 mL) and extracted with the use of De-ionised water. It was then washed with diethyl ether (2x 5mL) and water. The combined organic phases were washed with brine (7 mL) then dried with MgSO4. After filtering the solution it was rotary evaporated and the product was weighed (499 mg,  2.85 mmol, 142% yield) and sampled for 1H NMR using a CDCl3[NA-02-01 CRUDE]


IMG_0026.JPG

IMG_0027.JPG

After 7 days – change in solution colour noticed as it turned brown.


IMG_0030.JPG

Crude product oil

 

 

Part 2: pure product

TLC analysis was performed (10% EtOAc/pet. Ether). The solution was washed with ethyl acetate (x3) and mixed with silica then rotary evaporated until a solid mixture was formed. Column chromatography was done using a 5% eluent system (5% EtOAc/Petrol). 20 fraction samples were sampled for TLC  analysis (50% EtOAc/pet. Ether) but Only 7 fractions showed traces of the product (samples 11-18). These were collected in a pre-weighed RBF and rotary evaporated. The pure product was weighed (308 mg, 1.76 mmol) and sampled for 1H NMR with CDCl3 solvent along with a full analysis.  [NA-02-01-PURE]

crude oil to solid pure product.png

The process of rotary evaporating the crude solution after adding silica gel to produce a solid crude product to be purified through column chromatography

 

Column Chromatography set up.png

Column chromatography set up

 

TLC.png

  TLC of the 20 fractions from the HPLC purification. Samples 11 to 18 were collected to be rotary evaporated and analysed.

 

 NMR


CRUDE SAMPLE NA-02-01 

Scan FLUORO PROTON-17 OCT .jpeg

 

new mixture formed via polyconjugation but sample showed traces of DMF so TLC test was done under different conditions followed by coloumn chromatography purification.

 

PURE SAMPLE NA-02-01 

Scan FLUORO PURE-18 OCT.jpeg


 


FULL ANALYSIS OF PURE SAMPLE NA-02-01

NA WEEK 3 PURE PROTON-19 OCT.jpeg

NA WEEK 3 PURE CARBON-19 OCT.jpeg

NA WEEK 3 PURE DEPT-19 OCT.jpeg

NA WEEK 3 PURE COSY-19 OCT.jpeg

NA WEEK 3 PURE HSQC-19 OCT.jpeg

NA WEEK 3 PURE HMBC-19 OCT.jpeg


Reference 

X. Xia, X. Shu, K. Ji, Y. Yang, A. Shaukat, X. Liu and Y. Liang, J. Org. Chem., 2010, 75 (9), 2893–2902

Attached Files
SNAr mechanism for [NA-02-01].png
IMG_0026.JPG
IMG_0027.JPG
IMG_0030.JPG
Column Chromatography set up.png
TLC.png
crude oil to solid pure product.png
Scan FLUORO PROTON-17 OCT .jpeg
Scan FLUORO PURE-18 OCT.jpeg
NA WEEK 3 PURE HMBC-19 OCT.jpeg
NA WEEK 3 PURE HSQC-19 OCT.jpeg
NA WEEK 3 PURE COSY-19 OCT.jpeg
NA WEEK 3 PURE DEPT-19 OCT.jpeg
NA WEEK 3 PURE PROTON-19 OCT.jpeg
NA WEEK 3 PURE CARBON-19 OCT.jpeg