http://www.scielo.org.co/scielo.php?pid=S0122-74832009000300005&script=sci_arttext
The new compound 9 gave a molecular ion peak at m/z 331, corresponding to the molecular formula C20H17N3O2 as indicated by its EI-MS. The loss of 43 units (one acetyl group) generates the same mass spectrum as the acetamide 8.
The IR spectrum shows bands at 1704 and 1654 cm-1, assignable to two carbonyl groups. The N-H absorption bands were not observed in the region of 3300-3400 cm-1.
The 1H NMR spectrum showed, as expected, two singlets at d 22.4 and 23.9 ppm, which integrated three protons each. To the methylenic protons Figure 3.
X-Ray structure of the diacetamide 9 case, they appeared to be diasterotopic resonating at the high field frequencies d 4.75 and 5.46 ppm with a coupling constant J = 15 Hz, usual constant value to a germinal coupling. Of course, the aromatic protons were also assigned.
The 13C NMR spectrum showed all expected characteristic peaks at d 169.4 (ArN-CO-), 168.5 (ArindolN-CO-) ppm, in addition to a signal at d 117.3 ppm showing the presence of TCN in the molecule. Besides, methyl carbons at 23.9 (ArindolNCO-CH3) and 22.4 (ArNCO-CH3) ppm and the methylene carbon at d 42.8 ppm were also displayed in the 13C NMR.
N-(1-Acethyl-1H-indol-3-ylmethyl)-N-(2-cyanophenyl) acetamide (9)
A mixture of the amine 7 (0.50 g, 2.02 mmol), acetic anhydride (10.80 g, 98 mmol), and Et3N (0.44 g, 4.30 mmol) was heated at 100°C for 3 hours. Then, the reaction mixture was allowed to reach room temperature and then treated with 50 mL of aqueous NaOH and extracted with ethyl acetate (3 x 30 mL). The organic layer was dried over Na2SO4 and later dried in vacuum. Silica gel preparative chromatography (petroleum ether / ethyl acetate, 2:1) of the crude product afforded diacetamide 9 (0.53 g, 80%) as a white and stable solid. Rf 0.50 (petroleum ether/ethyl acetate, 1:1).
A mixture of the amine 7 (0.50 g, 2.02 mmol), acetic anhydride (10.80 g, 98 mmol), and Et3N (0.44 g, 4.30 mmol) was heated at 100°C for 3 hours. Then, the reaction mixture was allowed to reach room temperature and then treated with 50 mL of aqueous NaOH and extracted with ethyl acetate (3 x 30 mL). The organic layer was dried over Na2SO4 and later dried in vacuum. Silica gel preparative chromatography (petroleum ether / ethyl acetate, 2:1) of the crude product afforded diacetamide 9 (0.53 g, 80%) as a white and stable solid. Rf 0.50 (petroleum ether/ethyl acetate, 1:1).
 DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO .....FOR BLOG HOME CLICK HERE
Join me on twitter
Join me on google plus
 Googleplus
|
