Synthesis of an imine in water
SyntheticPage 578
DOI:
Submitted: December 11, 2012, published: December 20, 2012
Authors
Manish Vishnudutt Dhyani (manish_dhyani@hotmail.com)
Chemicals
Pyrrole-2-carboxaldehyde (Sigma-Aldrich)
Aminoacetonitrile hydrogensulfate (Sigma-Aldrich)
NaOH solution (4 N, prepared)Procedure
To a vigorously stirred mixture of Pyrrole-2-carboxaldehyde (2.000 g, 0.021 mol) and Aminoacetonitrile hydrogensulfate (6.483 g, 0.042 mol) in a 100 mL beaker, was slowly added 4 N NaOH solution. The slow addition of 4 N NaOH solution was continued till the reaction mixture attained a pH of 5-6. On further stirring, the product precipitated out as a faint yellow solid and was collected by filtration under vacuum. Washing the solid with water and drying under vacuum afforded 2.150 g (77 %) of a spectroscopically pure product which turned dark even on storage under nitrogen gas.
Author Comments
- After a pH of 5 is attained, the reaction is over in 5 minutes.
- Both the starting materials are soluble in water but the product is not. Consequently, as soon as the product is formed, it is removed from the reaction system and this probably drives the reaction to completion in a short time.
- This reaction was repeated a number of times affording yields ranging from 40-77 %.
Data
δH (200 MHz, CDCl3) ppm: 4.49 (2H, s, CH2), 6.28 (1H, m, Pyrr-H), 6.64 (1H, m, Pyrr-H), 6.96 (1H, m, Pyrr-H), 8.22 (1H, s, CH=N), 9.44 (1H, bs, NH).
Lead Reference
Vladimir V. Grushin, William J. Marshall, Water as an Ideal Solvent for the Synthesis of Easily Hydrolyzable Compounds: High-yield Preparation of 2-Pyrrolecarbaldimines and their CVD/ALD-Relevant Cu(II) Derivatives in H2O, Advanced Synthesis & Catalysis, 2004, 346:12, 1457-1460.
Other References
Fang Ping, Wu Chunying, Luo Shineng, Feng Yingying, Xie Minhao, Kuang Qinfang, Tao Guanjun, Zhu Yaochu, Ding Shaodong, Synthesis and labeling of a new brain perfusion imaging agent 99mTc-MRP20, Hejishu, 1993, 16:11, 690-694.
Supplementary Information
Keywords
aldehydes, amines, imine