The Research Of Amidine Reaction Of Benzonitrile With Electron Withdrawing Group On Its Para-position

Amidine compounds are widely used as antibiotics, anti-inflammatory drugs, insectrepellents and fungicides et al. With the expansion of its use, its method of synthesis alsoattracts more and more attention of scientific workers.At present, the synthesis route of Propamidine employs Pinner method and the reactionemits more than 10 times of hydrogen chloride gas and ammonia than products toenvironment. The reaction causes serious pollution and can not be used for industrialproduction. The mechanism of the Pinner reaction which was used to synthesize Propamidinewas investigated in this thesis. New synthesis route that using benzonitrile as raw material toconduct amidine reaction firstly, then conduct etherification reaction was proposed.P-nitrophenyl formamidine and p-fluorophenyl formamidine were synthesized byp-nitrobenzonitrile and p-fluorobenzonitrile without the use of hydrogen chloride andammonia, and their structures were characterized by IR. The influences of reactiontemperature, reaction time, the mole ratio of the raw material were investigated. The bestprescription was found after a series of orthogonal tests and single factor tests. The resultsshow that: high amidine production rate was obtained under the mild experimental conditionwhen p-nitrobenzonitrile and p-fluorobenzonitrile were used as the raw materials.P-nitrophenyl formamidine was synthesized with p-nitrobenzonitrile as raw material,sodium methoxide as catalyst, ammonium acetate as amination agent, and improved Pinnermethod as its synthesis method. The influences of these factors were analyzed after a series oforthogonal and single factor experiments, and its most apt reaction conditions are as follows:the ratio of p-nitrobenzonitrile, sodium methylate and ammonium acetate is 1:1:1.1, thereaction time and reaction temperature of the addition reaction are 3h and 45℃; the reactiontime and reaction temperature of the amido reaction are 18h and 40℃respectively. The yield of p-nitrophenyl formamidine can reach 90%. The synthesis process is mild andenvironmentally feiendly.P-fluorophenyl formamidine was synthesized with p-fluorobenzonitrile as raw material,n-acetyl-cysteine as catalyst, ammonium carbamate as amination agent, catalytic synthesismethod as its synthesis method. The influences of these factors were analyzed after a series ofsingle factor experiments, and its most apt reaction conditions are as follows: the ratio ofp-fluorobenzonitrile and n-acetyl-cysteine and ammonium carbamate is 1:1:0.55; the reactiontime and reaction temperature of the addition reaction are 20h and 50℃; the reaction time andreaction temperature of the amido reaction are 24h and 50℃respectively. The yield ofp-fluorophenyl formamidine can reach 92% and the synthesis process is mild andenvironmentally friendly.