A new protocol for Biginelli (or like) reaction under solvent-free grinding method using Fe (NO3)(3)center dot 9H(2)O as catalyst

A new protocol for Biginelli (or like) reaction has been developed under solvent-free grinding method using catalytic amount of hydrated ferric nitrate or clayfen. The advantage of this novel protocol lies in the avoidance of organic solvent, high yield, energy efficiency, variation of substrates, and use of inexpensive catalyst. The recycling of catalyst is also possible with clayfen for more than three times. Furthermore, the catalytic activity of ferric nitrate retains its efficiency in methanol and acetone as reaction medium. [GRAPHICS] .