A Practical, mild and efficient synthesis of 4,4´-(arylmethylene)bis(1H-pyrazol-5-ol) was achieved by simple condensation of aryl aldehyde and 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one using L Proline-NO3ionic liquid catalyst under ultrasonic sonication or conventional method. The notable features of this protocol are ionic liquid catalysed, short reaction time, high yielding, mild conditions also this method possess lower E factors. The scope gives excellent yield with electron rich and electron deficient aryl aldehyde as well as heterocycles. Also, the Gram-scale reaction shows reproducibility of our protocol. Reusability catalyst was conformed over number reaction there is no significant loss in reactivity of catalyst and yield of product was observed. Reusability of inexpensive ionic liquid, and environmentally friendly L Proline-NO3 ionic liquid catalyst allows us to developed broad substrate scope of bis pyrazol derivatives.