wt/vol

 

wt/vol

MW

moles

density

equivs.

yield

I

0.994 g

129.11

0.0077

 

1.0

 

II

1.488 g

189.21

0.0079

 

1.0

 

III

1.690 g

206.33

0.0082

 

1.1

 

IV

0.994 g

122.17

0.0081

 

1.1

 

V

50 mL

-

-

 

 

 

VI

1.885 g

300.31

0.0063

 

 

(82%)

 

Procedure:  100 mL 1-neck flask, stirbar, septum, N2 inlet

                  Dissolved 0.994 g of difluoroaniline (I) and 1.488 g of II in 50 mL of dry CH2Cl2.  Stirred at rt.  Added 1.690 g of DCC followed by 0.994 g of DMAP.  After 4.5 h, a white ppt had formed.  TLC (30:70 EtOAc-hexanes, UV) showed product spot at Rf 0.35.  The reaction mixture was filtered through Celite and concentrated by rotary evaporation.  The product was isolated by flash chromatography on silica gel using 30:70 EtOAc-hexanes as eluant.  The product was a white solid. 

 

1H NMR (CDCl3, 300 MHz) d 8.85 (br, NH), 7.10 (d, J = 7.1 Hz, ArH), 6.53 (m, ArH), 3.95 (s, COCH2), 3.01 (s, NCH3), 1.49 (s, C(CH3)3). 

 

notes

 

 

The reaction follows one of two possible pathways as illustrated below.