Efficient Solvent- and Catalyst-Free Syntheses of Imine Derivatives Applying the Pressure Reduction Technique: Remarkable Change of the Reaction Rate with the Phase Transition

• 作者: Hajime Nozaka Hiroyuki Ito Hitoshi Agematsu Kazuma Sasaki Kei Yagawa Koichi Maruyama Mami Yoshioka Motoyoshi Noike Risehiro Nonaka Shinji Ishizuka Shoko Suzuki Shujiro Sakaki Shun Oyamada Takashi Kuroishi Takeshi Kodama Tomomichi Nishino Tsuneyuki Sato Yasuo Yokoyama
• 来源期刊: 绿色与可持续化学(英文)
• 学科: 化学
• 关键词: SOLVENT-FREE CATALYST-FREE Pressure REDUCTION TECHNIQUE IMINE Reaction Rate Phase TRANSITION
• 年，卷（期）: 2018,（2）
• 页码范围: 167-179
• 页数: 13页
• 分类号: O6

摘要

Because imines could be used as convenient starting materials in various fields, the development of an easy synthetic method of imine was strongly desired. In response to this demand, we thought that it would be an effective synthesis method if an aldehyde and an amine could be reacted to give an imine in good yield under solvent- and catalyst-free conditions. In fact, we tried the reaction of benzaldehyde with various amines under solvent- and catalyst-free conditions followed by removal of water that was produced in the reaction system by a vacuum pump, and desired imines could be obtained in good yields. Observation of this reaction using a nuclear magnetic resonance spectrometer revealed that the reaction rate was extremely fast at the initial stage but slowed over time. However, the reaction of benzaldehyde with aniline differed greatly, and the reaction rate dramatically improved in 47 - 48 minutes after the start of the reaction. At this time, we found that the reaction system underwent a phase transition from the liquid phase to the solid phase.