Synthesis and Crystal Structures of 5-Bromo-3-Methoxysalicylidene-2-Furfurylimine (HL5) and 3-Nitrosalicylidene-2-Furfurylimine (HL6)

5-Bromo-3-methoxysalicylidene-2-furfurylamine (HL5) and 3-nitrosalicylidene-2-furfurylamine (HL6) were synthesized and studied by X-ray diffraction. Both structures are stabilized by strong intramolecular N1–H1···O2 hydrogen bonds. Both molecules exist as zwitterions. The structure of the HL6 molecule has a contribution of the tautomeric quinoid form.