3 research outputs found
How Mechanical and Chemical Features Affect the Green Synthesis of 1<i>H</i>‑Pyrazoles in a Ball Mill
This work investigated the chemical
and mechanical factors that
affect cyclocondensation reactions in a ball mill. Chemical characteristics
such as the use or non-use of a catalyst, amount of catalyst and reactants,
and product formation, as well as the yield and mechanical factors
such as rotation frequency and the number, diameter, and material
of the milling balls were evaluated. It was found that a rotation
frequency of 450 rpm is efficient for energy transfer to the reactants
because the conversion is higher at this rotation. The reaction was
highly dependent on the time (3 min) and amount of <i>p</i>-TSA (<i>p</i>-toluenesulfonic acid) utilized as catalyst
(10 mol %). Five steel balls of 10 mm were considered to be the ideal
number for the efficient mixing of the particles. For this work, the
ideal conditions determined were used for the green synthesis of a
series of 1<i>H</i>-pyrazoles