Introduction of new ionic liquid and its application as a catalyst for the synthesis of pyrano[2,3-d]pyrimidinones

Since the first synthesized ionic liquid (IL) introduced in 1914, ILs have caused a drastic change in synthetic chemistry. Nowadays, ILs are known as environmentally benign and convenient catalysts or dual solvent-catalysts to improve and facilitate organic reactions by omitting traditional solvents. This is due to their particular properties such as negligible vapor pressure, ability to dissolve many organic and inorganic substances, recyclability, good thermal stability, tunable viscosity, and miscibility with water and organic solvents.1 Pyran derivatives are common structural subunits in a variety of important natural products such as carbohydrates, alkaloids, polyether antibiotics, pheromones and iridoids. Pyrano[2,3-d]-pyrimidine derivatives have received more attention from chemists because of their biological activities such as, antiallergic, antihypertensive, cardiotonic, antibronchitic, antitumor hepatoprotective, antifungal, antimalarial, analgesic, antiviral evaluation, antibacterial, antileishmanial, vasodilator and herbicidal activities. In recent years, the use of acidic ionic liquid (Lewis and Bronsted) as catalyst has been a widely developed topic.2 So according to the properties mentioned, a new ionic liquid based on bis-imidazole is designed and used as the catalyst. The applicability of this reagent is studied in the promotion of the synthesis of pyrano[2,3-d]pyrimidinone derivatives. This method possess some advance such as ease of preparation of the catalyst, short reaction time, excellent yields.

کلیدواژه ها:

Ionic liquid ، Bis-imidazole ، Pyrano[2 ، 3-d]pyrimidinones