Synthesis Of O-Nitrobenzaldehyde For Preparation Of Its Schiff-Base Compounds With The Typical Amino Acidics Moieties

o-Nitrobenzaldehyde is one of important intermediates in organic syntheses,which has been widely used in the fields involving medicines,pesticides,dyes and others.It is also an indispensable intermediate in the preparation of cardio-cerebrovascular drugs.However,the production process of o-nitrobenzaldehyde is facing costly,complicated and environmental polluting at present.The synthetic route of o-nitrobenzaldehyde is systematically summarized and optimized in this paper.Futhermore,the preparation and characterization of Schiff base compounds derived from o-nitrobenzaldehyde and moiety amino acids were also investigated in this thesis.Reaction of N,N’-dimethylformamide,dimethyl sulfate and CH₃ONa gave the N,N’-dimethylformamide dimethyl acetal,which was further reacted with o-nitrotoluene to obtain the product o-nitrobenzaldehyde.The reaction conditions were also optimized from three aspects of oxidant types,oxidant dosages and oxidation temperature to find the optimal conditions:27.5%H₂O₂ was used as the oxidant,the molar ratio of N,N’-dimethyl-2-（2-nitrophenyl）vinylamine and H₂O₂ was 1:3.4,and the reaction was carried out at 0°C for 3 hours.The product could be obtained in 88.03%yield with99.07%purity（HPLC）,which was characterized by ¹H NMR,¹³C NMR,FT-IR,and UV-vis spectroscopies.o-Nitrobenzaldehyde contains active carbonyl group,which could react with primary amines to form Schiff base compounds.Treatment of thirteen L-amino acids contanining chiral carbon centers with o-nitrobenzaldehyde in enthanol in the presence of C₂H₅ONa/Na OH afforded ten o-nitrobenzaldehyde amino acid Schiff base compounds（T1～T10）,some of which were further reduced by Na BH₄ and acidified by HCl to gave five o-nitrobenzaldehyde L-amino acid reduced Schiff base compounds（B1～B5）.All present Schiff base compounds were well characterized by ¹H NMR,FT-IR,and UV-vis spectroscopies,of which o-nitrobenzaldehyde L-glycine acid reduced Schiff base compound B2 has been unambiguously established by single-crystal X-ray diffration,and the molecular structure and intermolecular hydrogen bonds have been discussed.