Submit Manuscript | http://medcraveonline.com Introduction Organic synthesis in water has attracted the attention of chemists for many years. Water is the nature’s solvent and possesses distinguished physical and chemical properties. It exhibits powerful hydrogen bonding and wide temperature range to remain in liquid state. In recent years, many organic transformations have been carried out in water. 1,2 Many organic solvents like benzene, methanol, toluene are carcinogenic and can be toxic to human health and cause an environmental menace by polluting the atmosphere. The replacement of volatile organic solvents in organic reaction is an important aim of green chemistry. 3,4 Earliest known examples of organic synthesis in water include Wohler’s urea synthesis and Baeyer and Drewsen’s indigo synthesis. 5–7 In recent years, several N, O, and S containing heterocyclic compounds are synthesized employing green synthetic protocols. It is of considerable interest to learn more about varied green technology platforms, which have been utilized for the synthesis of important heterocyclic scaffold. Being an important and growing area of research, these green protocols have been regularly reviewed. The present attempt is to review briefy water mediated organic reactions, resulting in the synthesis of various heterocyclic frame works and to highlight the signifcance as well as utility of water as a green solvent. Synthesis of substituted azo schiff bases 8 Zarei M et al. 8 reported the synthesis of pure azo Schiff bases (2) in high yields by mixing of the reagents either as aqueous slurry or by grinding at room temperature. Azoaldehyde (1) was prepared from p-anisidine and 2-hydroxy-3-methoxybenzaldehyde (o-vanillin) in aqueous medium at 0-5°C and then 1 was allowed to react with amines in a small amount of water at room temperature to produce azo Schiff bases (2) in excellent yields (Figure 1). Synthesis of pyrano[2,3-c]pyrazoles 9 Silica-water reaction medium was applied by Pravin et al. 9 for the synthesis of various pyrano[2,3-c]pyrazole derivatives based on the adsorptive nature of silica. The reaction was carried out under mild and neutral conditions accepting several functional groups present in the molecules thus reducing the possibility of many unwanted side reactions. Present method offers marked improvements with regard to product yield, reaction time, and greenness of procedure, avoiding hazardous organic solvents/toxic catalysts and provides a better, clean and practical alternative to the existing protocols (Figure 2). Figure 1 Synthesis of substituted azo Schiff bases. 8 Figure 2 Synthesis of Pyrano[2,3-c]pyrazoles. 9 Synthesis of aryldipyrromethanes 10 Taoufk et al. 10 have reported the oxidation of aryldipyrromethanes with p-chloranil (in dichloromethane), or DDQ (2,3-dichloro- 5,6-dicyano-1,4-benzoquinone) at room temperature to obtain the corresponding dipyrrins in good yields (50-78%) (Figure 3). Figure 3 Synthesis of aryldipyrromethanes. 10 Synthesis of pyrimido[4,5-d]pyrimidine 11 A practically convenient and eco-friendly aqua mediated synthesis of pyrimido[4,5-d]pyrimidines by the reaction of barbituric acid, aldehyde and urea or thiourea to yield pyrimido[4,5-d]pyrimidines MOJ Biorg Org Chem. 2017;1(7):239‒243. 239 © 2017 Sachdeva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. A mini-review on organic synthesis in water Volume 1 Issue 7 - 2017 Harshita Sachdeva, Sarita Khaturia Department of Chemistry, Mody University of Science and Technology, India Correspondence: Harshita Sachdeva, Department of Chemistry, College of Arts, Science and Humanities, Mody University of Science and Technology, Laxmangarh-332311 (Sikar), Rajasthan, India, Email drhmsachdevaster@gmail.com, harshitasachdeva.cash@modyuniversity.ac.in Received: December 3, 2017 | Published: December 13, 2017 Abstract The use of water as solvent in organic synthesis is one of the most powerful tool of green chemistry as it reduces emission of toxic chemicals in the environment thereby reducing pollution. Reactions can be carried out under mild conditions minimizing chemical waste with easy work up procedure enabling recycling of the catalyst. This review briefly highlights some important reactions carried out recently in water. Keywords: green chemistry, water, organic synthesis, green solvent MOJ Bioorganic & Organic Chemistry Review Article Open Access