Five-membered Heterocyclic Thiones. Part I. 1,3,4-Oxadiazole-2-thione

Construction of Five-Membered Heterocyclic Compounds via Radical Cyclization

Facile formation of five-membered N-heterocyclic zirconacycloallenoids.

The reaction of η(2)-iminozirconocene chloride complexes with trimethylsilylethynyl lithium leads to rapid C-C coupling at room temperature to yield the corresponding five-membered aza-zirconacycloallenoids. Such compounds were also obtained by trapping of in situ generated zirconocene with alkynyl imines.

Palladium-Catalyzed Amination of Unprotected Five-Membered Heterocyclic Bromides

An efficient method for the palladium-catalyzed amination of unprotected bromoimidazoles and bromopyrazoles is presented. The transformation is facilitated by the use of our newly developed Pd precatalyst based on the bulky biarylphosphine ligand tBuBrettPhos (L4). The mild reaction conditions employed allow for the preparation of a broad scope of aminoimidazoles and aminopyrazoles in moderate ...

Synthesis, Antimicrobial Activity and Heterocyclic Ring Transformation of 5-(Pyrazol-5-yl)-l,3,4-oxadiazole-2(3H)-thiones

A. S. Shawali, M. A . A bdallah , and M. E. M. Z ay ed Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt Reprint requests to Dr. A. S. Shawali. E-mail: [email protected] Z. Naturforsch. 55b, 546-552 (2000); received February 4. 2000 Ring-Chain Tautomerism. Heterocyclic Ring Transformation, 1,3,4-Thiadiazoles The synthesis and antimicrobial activity of a s...

5-(3,4,5-Trimeth­oxy­phen­yl)-1,3,4-oxadiazole-2(3H)-thione

The two rings in the title compound, C(11)H(12)N(2)O(4)S, are roughly coplanar [dihedral angle = 6.77 (8)°]. Whereas the two outer methyl groups of the three meth-oxy groups are almost coplanar with the aromatic ring to which they are attached [C-C-O-C torsion angles = 8.5 (3) and -8.3 (3)°], the methyl group of the central meth-oxy substituent is not [C-C-C-C = -78.4 (3)°]. The crystal packing...