Phosphorous pentoxide mediated synthesis of 5-HMF in ionic liquid at low temperature.

A convenient, mild and environment-friendly dehydration reaction of fructose in ionic liquid using phosphorous pentoxide (P(2)O(5)) has been investigated. The acidic nature of P(2)O(5) along with its hygroscopic properties has been successfully utilized to afford 81.2% yield of 5-hydroxymethylfurfural (5-HMF) at 50°C in 60 mins. Phosphoric acid yielded remarkably less 5-HMF even at higher temperature and longer reaction times. The reaction was optimized by varying different parameters and the results indicated that no rehydration products, such as levulinic acid or formic acid, were formed.