Highly Efficient Reusable Carboxy Group Functionalized Imidazolium Salts for a Simple and Cost-effective Preparation of pyrano[2,3-d]pyrimidinone Derivatives.

AIMS AND OBJECTIVE: In the current study, environmentally benign and cost-effective procedures were suggested for the preparation of carboxy group functionalized imidazolium salts, including [Cmmim]BF4 - or [Cmmim]Br- as a new, reusable Brønsted acidic ionic liquid (BAIL) catalyst. Then, the catalytic performance of [Cmmim]BF4 - or [Cmmim]Br- were successfully inspected towards the three---components one---pot preparation of pyrano[2,3-d]pyrimidinone derivatives 4a-4q. The mentioned procedures show short reaction times, easy work-up procedure, green conditions, high yields of the products, high potent of recovering, and reusing capability. The current study is useful and adequate for the application and development of imidazolium salts on the basis of green chemistry principles. MATERIALS AND METHODS: An aromatic aldehyde (1 mmol), barbituric acid (1 mmol), and malononitrile (1 mmol) were placed in a round---bottomed flask containing ethanol (5 mL). BAILs A and B (0.1 mmol, 10 mol%) were added to the mixture. The suspension was magnetically stirred at room temperature for an appropriate time (Table 2). After completion of the reaction, which was monitored by TLC (n---hexane:ethyl acetate = 3:1), the pure product was filtered off to separate the catalyst, washed with water, and recrystallized from ethanol to afford the pure compound. After separation of the product, the catalyst was recovered by evaporation of water, washed with Et2O, dried under vacuum for 2 h, and reused for the same reaction. RESULTS: The mentioned procedure shows short reaction times, easy work-up procedure, green conditions, high yields of the products, and high potent of recovering and reusing capability. CONCLUSION: In this study, we unveiled the synthesis of a new acetic acid functionalized ionic liquids [Cmmim]BF4 - BAIL A or [Cmmim]Br- BAIL B and their application for the preparation of pyrano[2,3-d]pyrimidinone derivatives via a three-component reaction among various aromatic aldehydes, barbituric acid, and malononitrile under mild and metal-free conditions. A wide range of pyrano[2,3-d]pyrimidinone derivatives bearing diverse functional groups was obtained in short reaction and excellent yields. Operational simplicity, recoverability, and reusability of catalysts, cheap and chemically stable reagents, high catalytic activity, easy work-up, and the eco-friendly procedure, make this method environmentally benign and cost-effective.

Producing (in) Europe and Asia, 1750-1850.

This essay argues for understanding and investigating the history of production, not primarily as a quantifiable economic phenomenon, but as a history of practice that involves the human senses, culture, governance, and material engagement. The vehicle it uses to make its case focuses on a brief examination of production cycles involving salts in various parts of Eurasia during the century that runs from approximately 1750 to 1850. The essay's approach suggests a history of production in Eurasia that was both locally variegated and transregionally networked. It further involved the interaction between people and their sociomaterial environments, the latter understood as the evolving outcome of interplay between material elements and processes; culturally rooted tastes and values; and variously organized efforts to stimulate, manage, and pursue cycles of production and use. This essay further reflects on how contemporary commentators and present-day historians have (re)configured the geography of these practices in a way that emphasizes divergence between Europe and Asia. Part of this reflection involves looking at what can happen when the historical investigation of production is based on economic analysis. So too does it involve thinking about the potential pitfalls of framing comparative histories.