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本文通过对苯甲酰丙酮与氨基硫脲缩合反应产物的合成和表征,确定了生成物的结构构型。对苯甲酰丙酮与氨基硫脲缩合反应过程中可能存在的加成反应、脱水反应和环合反应,首次采用量子化学计算方法在RB3LYP/6-31G的水平上研究了反应物、产物、中间体复合物和过渡态的优化构型和振动频率,频率分析确定了各中间体稳定性和过渡态的真实性,对每个过渡态均进行内禀反应坐标(IRC)计算以确认它连接着特定的反应物和产物。在RB3LYP/6-311G(2d,2p)的水平上得到了各驻点的能量,分析了苯甲酰丙酮与氨基硫脲的缩合反应途径和机理。机理结果分析表明苯甲酰丙酮与氨基硫脲发生反应时基本分4步进行,氨基硫脲的远端氨基加成到苯甲酰丙酮的远端羰基上生成TM1,TM1进而脱水生成稳定的中间产物PC1,然后PC1发生构象异构化生成TM2,最后氨基硫脲的仲氨氮原子加成到苯甲酰丙酮的近端羰基上形成一个稳定的五元环。
In this paper, by the synthesis of benzoyl acetone and thiosemicarbazide condensation reaction product characterization, to determine the structure of the product structure. The possible addition reaction, dehydration reaction and cyclization reaction were observed during the condensation reaction of benzoylacetone and thiosemicarbazide. The quantum chemistry calculation method was used for the first time to study the reaction products, products, intermediate The optimized configurations, vibrational frequencies and frequencies of bulk complexes and transition states confirm the stability of each intermediate and the authenticity of transition states. An intrinsic reaction coordinate (IRC) calculation is performed for each transition state to confirm that it is attached Specific reactants and products. The energy of each site was obtained at the level of RB3LYP / 6-311G (2d, 2p), and the condensation reaction pathway and mechanism of benzoylacetone with thiosemicarbazone were analyzed. The mechanism analysis showed that the reaction of benzoylacetone with thiosemicarbazide was basically divided into four steps. The addition of the amino group of the thiosemicarbazide to the carbonyl group at the distal carbonyl of benzoyl acetonide produced TM1. TM1 dehydrated to form a stable intermediate The product PC1, then PC1 conformational isomerisation to generate TM2, the final amino thiourea secondary amino nitrogen added to the proximal carbonyl carbonyl benzoyl acetone form a stable five-membered ring.