Silica-bonded N-propyltriethylenetetramine was
prepared via the reaction between 3-silicapropyl chloride
and triethylenetetramine. This heterogeneous solid base was
used as a catalyst for the synthesis of 4,40-(arylmethylene)
bis(1H-pyrazol-5-ols) by a one-pot condensation of aromatic
aldehydes with 3-methyl-1-phenyl-5-pyrazolone in 72–93 %
yields. The catalyst could be recycled several times without
any additional treatment.