organic compounds
In each of ethyl N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}glycinate, C16H19N5O3, (I), N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}glycinamide, C14H16N6O2, (II), and ethyl 3-amino-N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}propionate, C17H21N5O3, (III), the pyrimidine ring is effectively planar, but in each of methyl N-{2-amino-6-[benzyl(methyl)amino]-5-formylpyrimidin-4-yl}glycinate, C16H19N5O3, (IV), ethyl 3-amino-N-{2-amino-6-[benzyl(methyl)amino]-5-formylpyrimidin-4-yl}propionate, C18H23N5O3, (V), and ethyl 3-amino-N-[2-amino-5-formyl-6-(piperidin-4-yl)pyrimidin-4-yl]propionate, C15H23N5O3, (VI), the pyrimidine ring is folded into a boat conformation. The bond lengths in each of (I)-(VI) provide evidence for significant polarization of the electronic structure. The molecules of (I) are linked by paired N-HN hydrogen bonds to form isolated dimeric aggregates, and those of (III) are linked by a combination of N-HN and N-HO hydrogen bonds into a chain of edge-fused rings. In the structure of (IV), molecules are linked into sheets by means of two hydrogen bonds, both of N-HO type, in the structure of (V) by three hydrogen bonds, two of N-HN type and one of C-HO type, and in the structure of (VI) by four hydrogen bonds, all of N-HO type. Molecules of (II) are linked into a three-dimensional framework structure by a combination of three N-HO hydrogen bonds and one C-HO hydrogen bond.
organic compounds
(2R,4S)-2-(3-Methylthiophen-2-yl)-2,3,4,5-tetrahydro-1,4-epoxynaphtho[1,2-b]azepine, C19H17NOS, (I), crystallizes with a single enantiomer in each crystal, whereas its geometrical isomer (2RS,4SR)-2-(5-methylthiophen-2-yl)-2,3,4,5-tetrahydro-1,4-epoxy-naphtho[1,2-b]azepine, (II), and (2RS,4SR)-2-(5-bromothiophen-2-yl)-2,3,4,5-tetrahydro-1,4-epoxynaphtho[1,2-b]azepine, C18H14BrNOS, (III), both crystallize as racemic mixtures. A combination of one C-HO hydrogen bond and two C-H(arene) hydrogen bonds links the molecules of (I) into a three-dimensional framework; the molecules of (II) are linked into a C(4)C(4)[R22(7)] chain of rings by a combination of C-HN and C-HO hydrogen bonds; and in (III), where Z' = 2, a combination of four C-H(arene) hydrogen bonds and two C-H(thienyl) hydrogen bonds links the molecules into complex sheets. Comparisons are made with the assembly patterns in some aryl-substituted 1,4-epoxynaphtho[1,2-b]azepines.
organic compounds
(2RS,4SR)-7-Bromo-2-(2-methylphenyl)-2,3,4,5-tetrahydro-1H-naphtho[1,2-b]azepin-4-ol, C21H20BrNO, (I), and (2RS,4SR)-2-(3-methylthiophen-2-yl)-2,3,4,5-tetrahydro-1H-naphtho[1,2-b]azepin-4-ol, C19H19NOS, (II), both crystallize with Z' = 2 in the space groups P21/c and Cc, respectively; compound (II) crystallizes as a nonmerohedral twin, with twin fractions 0.183 (2) and 0.817 (2). The molecules of (I) are linked by O-HO and O-HN hydrogen bonds to form a cyclic centrosymmetric R44(16) tetramer. The molecules of (II) are linked by O-HO hydrogen bonds to form a C22(4) chain and these chains are weakly linked by a single C-H(thienyl) interaction to form a three-dimensional array. Comparisons are made with some related compounds.