A new quinolyl substituted 1,2,4-triazole, 3-(p-methylphenyl)-4-phenyl-5-(2- quinolyl)-1,2,4-triazole (L) and its iron(II) complex cis-[FeLE(NCS)2] (1), have been successfully synthesized and characterized by single-crystal X-ray diffraction. Both L and 1.Me2CO crystallize in monoclinic system but with different space groups: P21/c for L and C2/c for I.Me2CO. The L molecule is nonplanar and intermolecular C-H...N hydrogen bonds link two L molecules to form a dimer, which is further connected by intermolecular C-H...π interactions to produce 1D chains along the c axis. In complex 1-Me2CO, the iron(II) cation lies in a distorted octahedral environment with two cis-disposed NCS- ions. The L ligand coordinates via one triazole nitrogen and the quinolyl nitrogen. There is an intermolecular offset face-to-face π...π stacking interaction in the crystal packing of 1-Me2CO. 1 is the first complex with a quinolyl substituted 1,2,4-triazole.
A one-pot approach to ethyl 1,4,5-triaryl-lH-pyrazole-3-carboxylates has been developed in moderate to high yields. The tert-BuOLi-mediated Claisen condensation of 1,2-diarylethanones and ethyl oxalyl chloride efficiently provided the enolized lithium salts of ethyl 2,4-dioxo-3,4-diarylbutanoates, which in situ reacted with arylhydrazine hydrochlorides via a hydrochloric acid-promoted Knorr reaction to produce the exquisite triarylpyrazole-3- carboxylates. The procedure promises a convenient access to this highly crowded framework for drug discovery.
Jiaojiao ZhaiChunhui GuJianan JiangShunli ZhangDaohua LiaoLei WangDunru ZhuYafei Ji