All Notebooks | Help | Support | About
18th January 2017 @ 21:25

SNAr NA-02-02.png

 

Reagents

Equivalents

Quantity
 (mg / mL)

mmol

Molecular Weight g/mol

2-Fluorobenzaldehyde

1

2.5 g
2.1 mL

20.0 mmol

124.114

Pyrrolidine

1.5

(later became 2)

2.1 g (later 2.8g)
2.5 mL (+0.83mL= 3.33 mL total)

30.0 mmol
(became 40.0 mmol) 

71.123

K2CO3

1.5

4.1 g

30.0 mmol

138.205

DMF

-

20 mL

 

 

 

Procedure

Part 1: crude product

2-fluorobenzaldehyde (2.5 g, 20.0 mmol) and Pyrrolidine (2.8 g, 40.0 mmol) were added to a stirred solution of K2CO3 (4.1 g, 30.0 mmol) in 20 mL of DMF in a RBF and left to react overnight. After this time a miniwork up and TLC analysis were done (50% EtOAc/pet. Ether) and upon examination the plates showed the starting material was still present so the amine was added in excess (1 to 2 eqv of SM/amine) -amine (0.83mL) was added to the mixture in the RBF and left react futher for three hours. During that time two TLC analyses were done and showed that the reaction had still not gone to completion so it was decided that the mixture be left to react over the weekend.

 

1/ After this time the reaction mixture was diluted in diethyl ether (30 mL) and extracted with the use of 1:1 brine to De-ionised water (10mL) to dissolve build up in the RBF. De-ionised water (5mL) was used to show the separation of phases in the funnel. Some of the mixture was lost during the shaking of the separation funnel. More Diethyl Ether (40mL), deionized water (0.5mL) and 1:1 brine to De-ionised water (30mL) were added to the reaction mixture.

 

2/ After filtering the aqueous layer out the organic layer was washed with Diethyl ether (10mL) and 1:1 brine to De-ionised water (10mL) and filtered again. 

 

3/ The organic layer was collected and the aqueous layer was washed with Diethyl ether (20mL).

 

4/ After separation the organic layer was collected and was washed with 1:1 brine to De-ionised water (10mL) to separate again.

 

5/ The Combined organic phases were washed with brine (20mL) only and placed in a pre-weighed 250mL RBF. and product must be dried.
- forgot to dry the product with MgSO4 *

 

TLC analysis (50% EtOAc/pet. Ether) was undertaken and the mixture was evaporated in vacuo to give an oily crude product (4.4024 g, 125.58% yield). 

 

Part 2: pure product

To the crude product ethyl acetate and silica were added then rotary evaporated. - Some of the product was lost *

The product was then purified by column chromatography using (5% EtOAc/Petrol) eluent system. This resulted in 111 fractions. Fractions (18-36) contained SM, fractions (37-53) were rotary evaporated in a RBF then a TLC analysis showed that it contained traces of the product under short wave 254nm. TLC analysis showed fraction from 37 to 78 showed traces of product with faint fluorescence.  Fractions 79-80 showed faintly under 366nm but nothing was seen in fractions 81-87. Fractions (54-69) were added in the RBF and rotary evaporated and in another RBF fractions (70-81) were collected and rotary evaporated. They were then combined and the RBF containing the fractions (37-81) was left over the weekend was for the solvent to evaporate. The pure product (502 mg, 14.32% yield) was then sampled for IR with DCM using (ID7-ATR DIAMOND) and 1H NMR using a CDCl3 solvent [NA-02-02 PURE].  

 

 

 

pictures :

PART 1 - first steps after mixture was left to react overnight:

solution in RBF.JPG

 

after reflux.JPG

Solution left to stir and react 

 

left to reflux again for a week.JPG

leaving the mixture to react over the weekend

 

seperation.JPG

Seperation of reaction mixture -organic phases

 

 

TLC

 

(1)

TLC(1).JPG
       
TLC(1)longwave.JPG

 

(2)

TLC(2).JPG
       
TLC(2)longwave.JPG

 

 

 

DATA COLLECTION

 

NA-02-02-PURE.jpeg

NA-02-02- PURE

 

IMG_0904.jpg

IR analysis of pure sample

 

NA-02-02-PURE-PBC.jpeg

mass spec data of pure sample

 

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 NA-02-02.png
IMG_0904.jpg
NA-02-02-PURE-PBC.jpeg
NA-02-02-PURE.jpeg
after reflux.JPG
solution in RBF.JPG
seperation.JPG
left to reflux again for a week.JPG
TLC(2)longwave.JPG
TLC(1).JPG
TLC(1)longwave.JPG
TLC(2).JPG