2-(Pyrazin-2-yliminomethyl)phenol

Schiff bases from 2-hydroxy-1-naphthaldehyde have often been used as chelating ligands in the field coordination chemistry [1]. The Schiff base compounds can be classified by their photochromic and thermochromic characteristics [2].

A solution of 2-aminopipyrazine 1 (5.0g, 0.052 mol) and 2-hydroxybenzaldehyde aldehyde 2 (6.97g, 0.052 mol) in absolute ethanol (100 mL) was heated under reflux for 3 hrs. Cooling the mixture, filtering the precipitate and recrystalization from ethanol gave the Schiff base 3 as yellow crystals (3.72g, 33.97%).

Melting Point: 96-98°C (EtOH).

IR (KBr, cm^-1): 1594.9 (C=N), 1470 (C=C) and 1191.9 (C-N ).

¹H NMR (400MHz; CDCl₃) δ, ppm: 12.67 (s, 1H, OH), 8.80 (s, 1H, CH _olefinic), 8.67 (d, 1H,, CH _aromatic), 8.51 (s, 1H,CH _aromatic), 8.50 (d, 1H, CH _aromatic), 7.69 (d, 1H, CH _aromatic) , 7.27 (dd, 1H, CH _aromatic), 6.92 (d, 1H, CH _aromatic), 6.84 (dd, 1H, CH _aromatic).

Elemental Analysis: Calculated for C₁₁H₉N₃O (199.21): C, 66.32%; H 4.55%; N, 21.09 %. Found: C, 66.05%; H, 4.43 %; N, 21.14 %.