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14th November 2016 @ 21:22

Procedure.

0.212ml of 2-fluorobenzaldehyde and 0.322ml of bis(2-methoxymethyl)amine were added to a solution of 0.3g of calcium carbonate in 2ml DMF. The mixture was stirred and heated under an air condenser for 5 days. 

 

A dark 'woody' orange liquid was observed.

 

A mini-workup was performed on a small amount of product (washed with diethyl ether and distilled water) and a TLC was performed (diluted 1 drop of product and 2-fluorobenzaldehyde in 1ml of ethyl acetate)

The 'spots' annotated on the image as '366nm' shows that there is a conjugated system in the product, potentially the amine lone pair entering the benzaldehyde Π-system. But at this point it cannot be determined.

The product was washed with diethyl ether and distilled water three times. DMF was extracted with brine and the product was drived over magnesium sulphate. Solvent was removed in vacuo and NMR data was collected for the crude material.

Yield of crude product.

RBF = 30.8750g

RBF + Product = 31.1436g

Product = 0.2686g 

Theoretical = 0.474g 

Yield = 56.6%

 

NMR data to follow.

24th October 2016 @ 13:15

Procedure.

5ml of toluene was added to 0.13ml of 2-bromobenzaldehyde under an inert antomosphere (nitrogen) and stirred. Sequentially, 0.44ml of bis(2-methoxyethyl)amine, 0.006g of BiNAP, 0.28g of caesium carbonate and 0.002g of palladium(II) acetate were added to the mixture and stirred. The reaction was then degassed for 15 minutes and heated to ~150oC under an air condenser for 5days. 

Reaction scheme for the Buchwald-Hartwig amination of 2-bromobenzaldehyde

The reaction was added to a solution of unsaturated potassium carbonate, and then extracted with dichloromethane three times (3 x 20ml). The organic layer (bottom layer) was collected and washed with 10ml of brine, and extracted with 10ml dichloromethane. Organic layer was collected and dried with magnesium sulphate. Solvent was removed in vacuo leaving an orange oil. NMR analysis was performed and crude material yield calculated. 

 

NMR and yield. 

Theoretical yield: 0.225g

RBF: 58.7956g

RBF + product: 59.466g 

product: 0.6704g 

Yield: 297.95%

 

NMR shows that this was an unsuccessful reaction, there is evidence of a lot of starting material, and almost no evidence that the intended product was produced. This explains the very high yield obtained. Due to this, it was decided that another approach would be adopted.

NMR data to follow

Attached Files