Synthesis of the first representative of 2-pyrazolyl-1,3-diselenanes, 3,5-dimethyl-1-(prop-2-en-1-yl)-4-(1,3-diselenan-2-yl)-1 H-pyrazole.

The article focuses on the synthesis of the 1-allyl-3,5-dimethyl-1H-pyrazole-4-carbaldehyde (I) and propane-1,3-diselenol (II) in the presence of Me3SiCl catalyst. It says that the preparation of propane-1,3-diselenol (II) was performed by reductive cleavage of the Selenium bond in polytrimrthylene diselenide in the N2H4·H2O—KOH. It states that the reaction accompanied with heat evolution was completed in five minutes.