Experimental Study on Seawater Applications in Organic Reactions

Background: Total water resources account for only 2.5% of freshwater on earth, and only 1% of total water resources can be exploited by humans. The development of practical methods of seawater desalination and comprehensive utilization technology can help address the shortage of freshwater resources in the world, and achieve sustainable use of water resources to ensure sustainable development in a society. Direct seawater utilization currently involves industrial cooling water, water for agricultural irrigation, and flushing water. Applications in aqueous phase organic reactions, particularly the direct use of seawater in industrial organic synthesis reactions, are seldom reported. Methods: we used seawater instead of freshwater in selected basic organic chemical reactions. The application of seawater in aqueous phase organic reactions was systematically investigated. Six types of reactions were studied using freshwater and seawater, namely, preparation of acetanilide, synthesis of mandelic acid, Cannizzaro reaction, Hofmann degradation reaction, preparation of quinazolin-4-one, and preparation of adipic acid. Results: Seven organic compounds were produced. Results show that some organic reactions could directly use seawater or treated seawater as an alternative to freshwater. The yields of the reactions using seawater could be compared with literature values, or were even better than literature values. Conclusion: This research provides new opportunities for the comprehensive utilization of seawater. Some organic reactions could directly use seawater or treated seawater instead of freshwater. The use of seawater instead of freshwater for organic reactions in industrial production may greatly conserve freshwater resources and protect the environment. Keywords: 3-amino-2-chloro-4-methyl pyridine, anthranilic acid, hofmann degradation, quinazolin-4-one, seawater.