The title compound delavirdine (C23H32N6O4S) has been synthesized from nicotinamide, 4nitrophenylhydrazine and ethyl pyruvate. It was characterized by means of 1H NMR and 13C NMR. Its crystal and molecular structures were determined by Xray diffractometry. It belongs to the orthorhombic system, with space group P212121 with a=1.096 9(4)nm, b=1.152 5(4)nm, c=1.951 0(7)nm, α=90°, β=90°, γ=90°, V=2.468 5(15) nm3, Mr=488.61, Z=4, Dc=1.315 g/cm3, λ=0.071 073 nm, μ=0.172 mm-1, F(000)=1 040, the final R=0.040 7 and wR=0.090 5. A total of 14 875 reflections were collected, of which 4 851 were independent (Rint=0.040 7) and 4 099 were observed with I>2σ(I).