Reagents and conditions: a ArCOCH(R1)Br, TEA, DMF, Reflux. [7a (R=R1=H (71%); 7b (R = 4−OMe, R1=H (74%); 7c (R=H, R1=ph (68%); 7d (R=4−NO2, R1 = H (58%)]; b NaNO2, HCl, rt, 8 (78%); c Ac2O, AcOH, Reflux, 9 (72%); d CH2(CN)2, heating under solvent-free condition, 10 (77%)