Ball Milling Promoted N Heterocycles Synthesis MDPI
A solidsolid ball milling reaction of chalcone and phenylhydrazine catalyzed by NaHSO 4 ·H 2 O ( equivalents) was reported by Zhu and coworkers [ 41 ]. The reaction proceeded effectively using a highspeed ball mill at 1290 rpm to give 1,3,5triaryl2pyrazoline in good yields (up to 93%) ( Scheme 9 ).