title: Two carbamoyl-substituted dihydropyrimidines: potential mimics of dihydropyridine calcium channel blockers.
abstract: The structures of two conformationally similar 1,4-dihydropyrimidines with a novel carbamoyl substitution, viz. 6-methyl-5-(N-methylcarbamoyl)-4-phenyl-1,2,3,4-tetrahydropyrimidine-2-thione monohydrate, C13H15N3OS.H2O, (I), and 4-(4-chlorophenyl)-6-methyl-5-(N-methylcarbamoyl)-1,2,3,4-tetrahydropyrimidine-2-thione monohydrate, C13H14ClN3OS.H2O, (II), exhibit the structural features of 1,4-dihydropyridine calcium channel blockers. In both structures, the pyrimidine ring adopts a flattened boat conformation and the carbamoyl side chain is in an extended conformation with an anticlinal orientation. The phenyl ring occupies a pseudo-axial position with respect to the pyrimidine ring in these structures. Both compounds crystallize with one molecule of water, which participates in a two-dimensional hydrogen-bonding network. The molecules are linked into dimers by N-H...S hydrogen bonds in both structures.
authors.affiliation: Laboratory of X-ray Crystallography, Indian Institute of Chemical Technology, Hyderabad 500 007, India. ravikumar_iict@yahoo.co.in
authors.forename: K
authors.initials: K
authors.lastname: Ravikumar
authors.forename: B
authors.initials: B
authors.lastname: Sridhar
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry; D002121:Calcium Channel Blockers / Q000737:chemistry*; D002219:Carbamates / Q000737:chemistry; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry*
chemical_list: D002121:Calcium Channel Blockers; D002219:Carbamates; D011743:Pyrimidines