Extrusion of Formaldehyde from Bis(pyrazolylmethyl)Ethers on Heating

摘要

We recently showed that 1-substituted 3,5-dimethyl-pyrazolylmethanols I on heating to 200°C(2 h)are converted into bis(pyrazolylmethyl)ethers II[1].While studying the behavior of ethers II we revealed an unusual transformation.It was found that on heating to 250°C ethers II lose formaldehyde molecule with formation of dipyrazolylmethanes III which are usually obtained from pyrazoles and formaldehyde in the presence of acids[2,3].