One‐Pot Synthesis of 1,3,5‐Triarylpyrazoles

A series of novel 1,3,5‐triarylpyrazoles 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n , 3o , 3p , 3q , 3r , 3s , 3t , 3u , 3v , 3w , 3x were synthesized from flavanones, arylhydrazines, and trimethyl phosphate in an one‐pot procedure . Facile reaction process, easy after‐reaction workshop, and good yields are the distinct characteristics of the developed protocol. The target compounds were characterized by element analysis, infrared ray (IR), 1 H NMR spectra, and electrospray ionization‐mass spectrometry. The structure of representative compound 3h (C 23 H 20 N 2 O 3 , M r = 372.42) was further confirmed by X‐ray diffraction. It crystallizes in monoclinic, space group P 2 1 / c , a = 8.9720(5), b = 24.5523(13), c = 8.9687(6) Å, α = 90.0000, β = 102.6417(17), γ = 90.0000°, V = 1927.76(20) Å 3 , Z = 4, μ(MoKα) = 0.086, F (000) = 784, D c = 1.283 g/cm 3 , the final R = 0.0349 and wR = 0.0844 for 1668 observed reflections ( I > 2σ( I ))