“…A mixture of compound 3 (2.98 g, 0.01 mol), acetylchloride (0.78 g, 0.01 mol) in pyridine (30 ml) was refluxed for 2 h. The reaction mixture was poured onto acidified water (pH ∼ 3), the solid formed was filtered off, washed with water, dried and crystallized to give compound 11 in yield: 60%; m.p: 195 • C (AcOH); IR (KBr) ν max : 3257 and 1671 cm −1 corresponding to ν(NH) and ν(C=O, acetyl), respectively. 1…”