Synthesis of 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione and structural characterization of its polymorphs and complexes with 12-group metal iodides

Abstract

A novel cyclic thiourea, 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione (L), was synthesized by the reaction of N-(1-tosylethyl)thiourea with potassium enolate of acetylacetone followed by acid-catalyzed dehydration of the obtained 5-acetyl-4-hydroxy-4,6-dimethylhexahydropyrimidine-2-thione. Its polymorphs and complexes with zinc, cadmium, and mercury iodides were studied by X-ray diffraction. Two polymorphs of 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione differ in ring conformation and packing manner. In the monomeric cadmium complex [CdL 2 I 2 ], the central atom is tetrahedrally coordinated in the standard manner by iodine and thiocarbonyl S atoms, while in the dimeric mercury complex [Hg 2 L 2 I 4 ], every mercury atom is coordinated by two bridging I atoms, one terminal I atom and one thiocarbonyl S atom of the ligand. In the polymeric zinc complex [ZnLI 2 ], the zinc tetrahedra are linked by the bidentate bridging 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione molecules through thiocarbonyl S atom and acetyl O atom.

Cobalt(II), nickel(II), and copper(II) complexes of 14-membered hexaazamacrocycles: synthesis and characterization

“…There are many examples in literature [53][54][55][56] In the earlier reported polymeric complexes with similar ligands, [CuLN 3 ] n [ClO 4 ·3/ 2H 2 O] n (L = 3,10-bisbenzyl-1,3,5,8,10,12-hexaazacyclotetradecane or 3,10-bisbenzyl-6,13-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane), Cu(II) ions are bridged by single azide in the μ-1,3 (end-to-end) bridging mode in a trans-position with respect to the azide, and each heterocyclic ligand forms bonds with one copper [59].…”