title: 2-Ethyl-1-[5-(4-methylphenyl)pyrazol-3-yl]-3-(thiophene-2-carbonyl)isothiourea: molecular ribbons containing three types of hydrogen-bonded ring.
abstract: The title compound, C18H18N4OS2, was prepared by reaction of S,S-diethyl 2-thenoylimidodithiocarbonate with 5-amino-3-(4-methylphenyl)-1H-pyrazole using microwave irradiation under solvent-free conditions. In the molecule, the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.814 (4) and 0.186 (4), and the bonded distances provide evidence for polarization in the acylthiourea fragment and for aromatic type delocalization in the pyrazole ring. An intramolecular N-H···O hydrogen bond is present, forming an S(6) motif, and molecules are linked by N-H···O and N-H···N hydrogen bonds to form a ribbon in which centrosymmetric R2(2)(4) rings, built from N-H···O hydrogen bonds and flanked by inversion-related pairs of S(6) rings, alternate with centrosymmetric R2(2)(6) rings built from N-H···N hydrogen bonds.
authors.affiliation: Heterocyclic Compounds Research Group, Department of Chemistry, Universidad de Nariño, AA 1175 Pasto, Colombia.
authors.forename: Edison
authors.initials: E
authors.lastname: Castro
authors.affiliation: Heterocyclic Compounds Research Group, Department of Chemistry, Universidad de Nariño, AA 1175 Pasto, Colombia.
authors.forename: Henry
authors.initials: H
authors.lastname: Insuasty
authors.affiliation: Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, AA 25360 Cali, Colombia.
authors.forename: Braulio
authors.initials: B
authors.lastname: Insuasty
authors.affiliation: Departamento de Química Inorgánica y Orgánica, Universidad de Jaén, 23071 Jaén, Spain.
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.affiliation: School of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland.
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D013876:Thiophenes / Q000737:chemistry*; D013890:Thiourea / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: C000596813:2-ethyl-1-(5-(4-methylphenyl)pyrazol-3-yl)-3-(thiophene-2-carbonyl)isothiourea; D013876:Thiophenes; D013890:Thiourea
keywords: charge-assisted hydrogen bonding; crystal structure; isothiourea; microwave irradiation; molecular ribbons; pharmacological activity; solvent-free conditions; thiophene