Synthesis and crystal structures of 2-amino-3-cyano-4-(2-chlorophenyl)-1,4-dihydro-2H-pyrano[3, 2-h]quinoline and 2-amino-3-cyano-4-(2-chlorophenyl)-8-(2-chlorobenzylidene)-1,4,5,6,7,8-hexahydrobenzo[b]pyran

The title compounds 2-amino-3-cyano-4-(2-chlorophenyl)-1,4-dihydro-2H-pyrano[3, 2-h]quinoline 1 (C₁₉H₁₂ClN₃O, M _r = 333.77) and 2-amino-3-cyano-4-(2-chlorophenyl)-8-(2-chlorobenzylidene)-1,4,5,6,7,8-hexahydrobenzo[b]pyran 2 were synthesized and crystallized. The crystals of compound 1 are triclinic, space group P-1, a = 7.488(2), b = 9.127(3), c = 12.252(3) Å, = 73.58(2), = 78.38(2)°, = 75.39(2), Z = 2, V = 769.5(4) ų; The compound 2 crystallizes in space group P2₁/n, with cell parameters a = 13.582(2), b = 8.974(1), c = 16.960(2) Å, = 103.34(1)° and D _calc = 1.352 g/cm^–3 for Z = 4. X-ray analysis reveals that atoms C(1)—C(5) and O form a pyran ring in compound 1, which adopts half-chair conformation. In compound 2 the atoms C(12)—C(16) and O form a pyran ring which adopts boat conformation, another six-membered ring (C(8)—C(13)) adopts a half-chair conformation. In addition, there are intermolecular hydrogen bonds in the crystal structures 1 and 2.     

Crystal and molecular structures of 1-(2-carboxypropan-2-ylamino)-3-(1-naphthyloxy) propan-2-ol (1) (C17H21NO4) and 1-(2-carbamoyl propan-2-ylamino)-3-(1-naphthyloxy) propan-2-ol (2) (C17H22N2O3)

The crystal structures of two new-adrenergic antagonists, derivatives of propranolol containing 2-methylalanine fragment are described in this paper. The space groups and unit-cell parameters are: compound1 (C₁₇H₂₁NO₄): monoclinic, space groupP2₁/n,a=5.787(1),b=18.703(4),c=23.526(5)Å,=96.49(2)°; compound2 (C₁₇H₂₂N₂O₃): triclinic, space groupP¯1,a=8.321(1),b=10.121(1),c=10.368(1)Å,=109.49(1)°,=90.49(1)°, =103.48(1)°. The structures were solved by direct methods and refined with full matrix least-squares techniques toR indices of 0.055 and 0.049, respectively. The molecules of compound1 exist in the crystal as dual ions. The molecules of compound2 are compact and their external chain is twisted in a characteristic way (similar to that found in peptides).     

Structure of 4,6-dimethylisothiazolo[5,4-b]pyridin-3(2H)-one and its 2-[4-(2-methylphenyl) piperazin-1-ylmethyl] derivative

The crystal and molecular structures of 4,6-dimethylisothiazolo[5,4-b]pyridin-3(2H)-one, C₈H₈N₂OS, 1, and its 2-[4-(2-methylphenyl)piperazin-1-ylmethyl] derivative, C₂₀H₂₄N₄OS, 2c, are described. These compounds crystallize in the monoclinic system in the space group P2 ₁/c. The cell constants for compound 1 are a = 5.049(1), b = 14.897(1), c = 11.330(1) Å, = 98.07(1)°, Z = 4, T = 293 K, and D _cal = 1.419 g cm^–3, and for compound 2c are a = 15.525(1), b = 12.021(1), c = 10.911(1) Å, = 106.42(1)°, Z = 4, T = 293 K, and D _cal = 1.253 g cm^–3 The structures were solved by direct methods and refined to R values of 0.0411 and 0.0380 for 1640 and 3504 reflections for 1 and 2c, respectively. The analysis of the geometry and difference electron density map reveal that the dimethylisothiazolopyridine 1 exists in the amino tautomeric form in the crystalline state. The conformation of the o-methylphenylpiperazine part of the molecule 2c strongly depends on the substituents effect in the phenyl ring and is very similar to those observed in crystals for other investigated arylopiperazine derivatives of the isothiazolopyridine.     

Crystal and molecular structures of 1-(2-iso butylylcarbamoyl propan-2-ylamino) 3-(1-naphthyloxy)propan-2-ol hydrochloride (1) (C21H31N2O3Cl) and 1-(2-isobutyloxycarbonylo propan-2-ylamino) 3-(1-naphthyloxy)propan-2-ol hydrochloride (2) (C21H30NO4Cl)

This paper shows the crystal structures of two new-adrenergic antagonists, derivatives of propranolol, which were determined with three-dimensional x-ray diffraction data. The space groups and unit-cell parameters are: compound1 (C₂₁H₃₁N₂O₃Cl) monoclinic space groupP2₁/c,a=20.523(4),b=6.909(2),c=15.950(2) Å,=105.03(1)°; compound2 (C₂₁H₃₁NO₄Cl) monoclinic space groupP2₁/c,a=6.364(2),b=36.043(8),c=10.149(1) Å,=104.48(2)°. The structures were solved with direct methods, and refined with full-matrix least-squares techniques toR indices of 0.059 and 0.067, respectively. The-CH(OH)-CH₂-NH-sections of the side chains show the conformation approximate togauche.     

Synthesis of 3,4-dihydro-3,3-dimethyl-1(2H)-acridinone

The acridinone derivative 3,4-dihydro-3,3-dimethyl-1(2H)-acridinone (4) has been prepared in a two step fashion and the molecular structure confirmed by X-ray diffraction. Compound4 crystallizes in the space group P2_l/n witha=6.022(2),b=21.111(2),c=9.604(2) Å, =99.97(2)°, andZ=4. The single crystal analysis showed the acridinone tricyclic ring is virtually planar except in the gem-dimethyl position of C(3) which presented a half-chair conformation.     

Synthesis and crystal structures of two potential gem-di(pyrazolyl)cycloalkane ligands, 1,1-di(pyrazol-1-yl)cyclohexane [C6H10(C3N2H3)2] and 1,1-di(pyrazol-1-yl)cyclopentane [C5H8(C3N2H3)2]

The species 1,1-di(pyrazol-1-yl)cyclohexane, C₁₂H₁₆N₄, crystallizes in the monoclinic space group P2₁/c with a = 8.340(2), b = 14.281(5), c = 10.153(3) Å, = 106.86(2)°, and Z = 4. The cyclohexane moiety has the chair conformation. The congener, 1,1-di(pyrazol-1-yl)cyclopentane, C₁₁H₁₄N₄, while not isomorphous, also crystallizes in space group P2₁/c with a = 14.350(2), b = 6.776(1), c = 11.043(2) Å, = 100.68(1)°, and Z = 4. The cyclopentane ring has a conformation in which four carbon atoms are essentially coplanar, while the fifth (that with the two pyrazolyl substituents) lies 0.63 Å from this plane, resulting in a bend of 41.3° across the C(2)···C(5) vector. The hydrogen atoms in each structure were located directly and their coordinates refined.     

Crystal and molecular structure of 1-phenyl-3-(2-hydroxyphenylamino)-2-buten-1-one,C16H15NO2

Orange, yellow, and colorless crystals were obtained for the title compound. The orange crystals are triclinic, space groupP¯1,a=9.181(2),b=10.734(2),c=15.245(3) Å,=73.06(2),=79.21(2), =67.83(2)°,V=1325.9(5) ų,Z=4. Two different symmetry-independent molecules (moleculeA andB) were determined in the crystal unit. The conformation ofA is stabilized by an intramolecular H bond from the amino NH to the keto and phenolic O atoms [1.89(2) and 2.38(2) Å, respectively]. The conformation ofB is stabilized by only one intramolecular H bond, from the amino NH to the keto O atom [1.925(2) Å]. The colorless crystals (moleculeC) are monoclinic, space groupP2₁/n,a=11.883(3),b=11.004(3),c=10.053(3) Å,=95.93(3)°,V=1307.5(6) ų,Z=4. This conformation is stabilized by one intramolecular H bond, the same as in B, with N-HO, 1.84(3) Å. An intermolecular H bond is observed forA,B, and C, O-HO, 2.634(2), 2.640(2), and 2.697(2) Å, respectively. The yellow crystals are adducts with ethanol (¹H NMR, infrared and GC measurements).     

Crystal structures and spectroscopic properties of copper(II) and zinc(II) complexes with the macrocycle 1,4,7-tris(2-pyridylmethyl)-1,4,7-triazacyclononane

Two novel transition-metal copper and zinc complexes [(CuL)₂]·(ClO₄) (1) and [(ZnL)]·(ClO₄)₂ (2) (L = 1,4,7-tris(2-pyridylmethyl)-1,4,7-triazacyclononane) have been synthesized and structurally determined. The two complexes are both crystallized in monoclinic space group P2(1)/c with a = 14.318(4), b = 17.214(5), c = 22.403(7) Å, = 93.096(6)°, V = 5522(3) ų, and Z = 4 for 1 and a = 9.371(2), b = 17.615(4), c = 17.579(4) Å, =104.070(4)°, V = 2814.6(11) ų, and Z = 4 for 2. The center metal ions are coordinated to six nitrogen atoms, three of which are from triazacyclononane and other three from the pendant-arms 2-pyridylmethyl, forming a slightly distorted octahedral geometry. Two complexes have been characterized by element analysis, infrared spectroscopy, and the UV–Vis and ESR spectra for 1 have also been determined.     

Synthesis and crystal structures of 5-amino-1-(2-hydroxyethyl)imidazole-4-carboxamide and 5-amino-1-(2-chloroethyl)-4-cyanoimidazole

Both 5-amino-1-(2-hydroxyethyl)imidazole-4-carboxamide (AHIC) and 5-amino-1-(2-chloroethyl)-4-cyanoimidazole (ACCI) have been synthesized and crystallized in the monoclinic space group P2₁/c, Z = 4, with a = 8.420(2), b = 9.759(2), c = 10.583(2) Å, = 111.80(2)° for AHIC and a = 6.139(1), b = 8.522(2), c = 15.156(3) Å, = 96.71(2)° for ACCI. Differences in the molecular geometries of the two compounds are attributed to the differences in the substituents at the 1- and 4-positions of the imidazole ring. The molecular conformation of AHIC is stabilized by intramolecular hydrogen bonding between the 5-amino and the vicinal carboxamide moiety, resulting in an extended planar structural pattern. The presence of the cyano group in the 4-position of ACCI prevents the formation of such an intramolecular hydrogen bond. Both the crystal structures are stabilized by networks of intermolecular hydrogen bonds.     

Crystal and molecular structures of 1-(2-methyloxycarbonylo-propan-2-ylamino)-3-(1-naphthyloxy) propan-2-ol hydrochloride (1) (C18H24NO4Cl) and 1-(2-methylcarbamoylpropan-2-ylamino)-3-(1-naphthyloxy) propan-2-ol (2) (C18H24N2O3)

The crystal structures of two new-adrenergic antagonists, derivatives of propranolol, are reported in this paper. The space groups and unit-cell parameters are: compound1 (C₁₈H₂₄NO₄Cl), monoclinic,P2₁,a=7.215(1),b=8.591(1),c=15.017(1)Å,=95.64(1)°; compound2 (C₁₈H₂₄N₂O₃), monoclinic,P2₁/c,a=10.218(3),b=21.616(5),c=8.124(2)Å,=101.28(2)°. The structures were solved with direct methods and refined by full-matrix least-squares techniques toR indices of 0.036 and 0.066, respectively. The molecule of compound1 has an extended external chain, and thus its structure is linear, whereas the molecule of compound2 is compact, and its external chain is twisted in a characteristic way, as is the case of peptides.     

Geometry of lidocaine-like molecules: 2. Crystal structures of 2-benzyl-2-(1-piperidinyl)-N-(2,6-dimethylphenyl) acetamide and its hydrochloride hemihydrate

The title compounds both crystallize in the monoclinic space group P2₁ (Z = 4), with a = 12.574(1), b = 9.653(1) c = 16.483(1) Å, and = 91.84(1)° for the free base and a = 10.991(2), b = 16.864(3), c = 12.030(2) Å, = 99.35(3)° for the hydrochloride. The most important factors affecting conformation of the molecules are: ortho-substitution of the benzene ring in the acetanilide system and substitution of the C atom. Surprisingly, the conformation does not depend on the protonation state of the amine nitrogen atom, which greatly affects packing and hydrogen bonding patterns in the crystalline state. The conformation in which the H atom of the charged amine group is in a trans position to the main backbone of the molecule, is probably responsible for the antiarrhythmic activity, while a gauche conformation promotes local anaesthetic action. The separation of the lipophilic (xylidine) and amine groups, being two important pharmacophores, equals about 4.7 Å in the studied compounds and other structures comprising the amino-2,6-dimethyl-acetanilide system.     

4,5-Bis(benzylthio)-1,3-dithiole-2-thione compounds: crystal structures of [(p-XC6H4CH2)(p-XC6H4CH2)dmit: X=Y=OMe; X=Y=NO2; and X=OMe, Y=NO2]

4,5-Bis(benzylthio)-1,3-dithiole-2-thiones, [(p-XC₆H₄CH₂)(p-XC₆H₄CH₂)dmit: X=Y=OMe (2); X=OMe, Y=NO₂ (3); and X=NO₂] (4)] have been prepared from benzyl chlorides and [NEt₄]₂[Zn(dmit)₂]. Isostructural compounds, 2 and 3, crystallize in the triclinic space group (Z = 2) with a = 5.2920(10), b = 10.537(2), c = 18.961(4) Å, = 102.79(3), = 96.33(3), = 98.67(3)° for 2; a = 5.292(8), b = 10.528(12), c = 19.01(2) Å, = 102.74(9), = 96.26(11), = 98.56(11)° for 3. Compound 4 also crystallizes in the space group (Z = 4), with a = 9.296(8), b = 13.993(18), c = 16.186(4) Å, = 106.68(3), = 89.63(3), = 99.38(6)°. Molecular differences between 2 and 3, on one hand, and 4, on the other, arise in the disposition of the aryl rings relative to the dmit group. Short S---S contacts in 2 of 3.320(2) Å [S3---S3 ⁱ (symmetry operation: i: –x + 1, –y + 1, –z)] and in 3 of 3.314(5) Å [S3---S3 ⁱ (symmetry operation: i: –x + 1, –y, –z + 1)] link molecules into pairs. In 4, an S5A---S2B contact of 3.516(5) Å links two independent molecules, A and B, into bimolecular units, which are further connected into chains by S2A---S5B ⁱ contacts (symmetry operation: i: x, y, z – 1) at 3.569(5) Å. C–H---O hydrogen bonds are also present in 3 and 4.     

The structure of 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole hydrogen fumarate

The crystal and molecular structure of the title compound has been determined by X-ray analysis. The 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole ion cocrystallizes with fumaric acid, (C₁₉H₂₂N₄F⁺·C₄H₃O ₄ ^– ), in space group P-1 with cell dimensions a = 9.938(1), b = 10.131(1), c = 12.712(1) Å, = 86.57(1), = 69.41(2), and = 67.22(2)°. The piperazine N4 atom is protonated and contacts the deprotonated O atom of the fumarate anion through a hydrogen bond. The benzimidazole ring is nearly planar and makes a dihedral angle of 111.25(12)° with the fluorophenyl ring. The piperazine ring adopts a chair conformation.     

Synthesis and crystal structure of 1-acetyl-3-bromo-3-phenylazetidine and 1-phenyl-2-(N-acetyl-N-formyl)-aminoethanone

1-Acetyl-3-bromo-3-phenylazetidine (1), C₁₁H₁₂BrNO, has been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2 ₁/c with a = 8.633(1), b = 7.461(1), c = 17.204(1) Å, = 98.403(7)°, V = 1096.2(2) ų, Z = 4, D _calc = 1.540 g cm^–3. The azetidine ring is nearly planar since the four atoms are within ±0.039(5) Å of the mean square plane calculated for the heterocycle. The attempt to obtain a highly strained 2-azetine derivative from the above compound gave, surprisingly, 1-phenyl-2-(N-acetyl-N-formyl)-aminoethanone (2), C₁₁H₁₁NO₃. This compound has been also characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2₁2₁2₁, with a = 5.4719(3), b = 8.3205(6), c = 23.298(3) Å, V = 1060.7(2) ų, Z = 4, D _calc = 1.286 g cm^–3. The aminoethanone residue is in a near planar conformation where the torsion angles are 7(2)° for N–C–C–=O and –173(2)° for N–C–C–C(Ph).     

X-ray crystallographic and molecular modeling studies of 1-(2,6-difluorobenzoyl)-5-(4-chlorophenyl)biuret

Crystals of 1-(2,6-difluorobenzoyl)-5-(4-chlorophenyl)biuret (BFB), C₁₅H₁₀N₃O₃F₂Cl, were grown by evaporation from an acetonitrile solution. Two polymorphs were obtained. The first polymorph (BFB1) crystallized in the monoclinic space group P2₁/c (Z = 4) with unit cell a = 13.021(3), b = 5.293(1), c = 21.199(6) Å, and = 97.34(2)°. The second polymorph (BFB2) crystallized in the orthorhombic space group P 2₁2₁2₁ (Z = 8) with a = 10.513(1), b = 10.806(1), and c = 26.685(1) Å. The results of crystallographic and molecular modeling studies on BFB were in good agreement. The compound has an extended conformation with the benzene rings coplanar and the intervening –CONHCONHCONH– moiety rotated out of the plane due to steric effects from the two fluorine atoms.     

Crystal structures of a series of 3,7-bis-(arylazo)-1,3,5,7-tetraazabicyclo[3.3.1]nonanes

The crystal and molecular structure of a series of 3,7-bis(arylazo)-1,3,5,7-tetraazabicyclo[3.3.1] nonanes (1a–d) have been determined by single crystal X-ray diffraction analysis. All four compounds have the same feature, that the tetraazabicyclononane unit assumes a cage-like structure with the aryltriazene moieties lying parallel to one another so that the aryl rings are held together by – stacking. Crystal data: 1a C₁₇H₁₈N₁₀O₄, triclinic, space group P – 1, a = 9.8899(10), b = 13.0845(13), c = 16.458(2) Å, = 94.095(2)°, = 107.004(2)°, = 111.027(2)°, V = 1863.5(3) ų and Z = 4; 1b, C₁₉H₁₈F₆N₈, orthorhombic, space group Pbca, a = 15.3210(8), b = 10.9512(6), c = 24.5698(13) Å, V = 4122.4(4) ų and Z = 8; 1c C₁₉H₁₈N₁₀, monoclinic, space group P2₁/n a = 6.3742(6), b = 13.7343(13), c = 21.542(2)Å, = 97.738(2)°, V = 1868.8(3) ų, and Z = 4; 1d, C₁₉H₁₈N₁₀, monoclinic, space group P2₁/c, a = 18.205(2), b = 17.398(2), c = 12.784(12) Å, = 109.480(2)°, V = 3818.0(6) ų, and Z = 8.     

Molecular structures of (tBu)Ga(S2CNnPr2)2 and (iPrO)Ga(S2CNEt2)2: An example of an unusual ligand pseudorotation

The molecular structures of (^tBu)Ga(S₂CNⁿPr₂)₂ (1) and (ⁱPrO)Ga(S₂CNEt₂)₂ (2) have been determined. The variation in the geometries observed for bis-dithiocarbamate compounds of gallium, (X)Ga(S₂CNMe₂)₂ (X=Cl, ⁱPrO, ^tBu) do not lie along the Berry pseudorotation pathway for the square-based pyramid to trigonal bipyramid geometrical transition. Instead, the structures appear to lie on an unusual ligand two-step, Texas, pseudorotation mechanism which results in a highly distorted trigonal bipyramidal geometry. Crystal data: (1) monoclinic, P2₁,/c, a = 9.786(1), b = 29.218(3), c = 9.452(1) Å, = 108.379(9)°, V = 2564.7(5) ų, and Z = 4. (2) Monoclinic, P2₁ /c, a = 10.980(3), b = 15.673(4), c = 12.461(3) Å, = 97.47(2)°, V = 2126.2(9) ų and Z = 4.     

Crystal and molecular structure ofN-[1-(2-phenylethyl)-4-piperidinylium]-N-phenylpropanamide (fentanyl) citrate-toluene solvate

The crystal structure of fentanyl has been determined as part of a structure-activity relationship study on a congeneric series of 4-anilinopiperidines. The compound crystallizes as a citrate toluene solvate, C₂₂H₂₈N₂O · C₆H₈O₇ · C₇H₈, in the monoclinic space groupP2₁/c witha = 18.292(6),b = 9.825(4),c = 19.479(4) Å, = 107.43(3) °, andZ = 4. The structure was solved by direct methods using the program Simpel, and refined by block-diagonal least squares to anR value of 0.092. The torsion angle that describes the conformation of theN-phenyl ring relative to the piperidine ring is 123 ° and differs from that found in other 4-substituted anilinopiperidines (172–177 °).     

Molecular structures of M(tfac)3 (M=Al, Co) and Cu(H2O)(fod)2: Examples of unusual supramolecular architecture

The molecular structures of Al(tfac)₃ (1), Co(tfac)₃ (2) (H-tfac = 1,1,1-trifluoroacetylacetone) and Cu(H₂O)(fod)₂ (3) (H-fod = 1,1,1,2,2,3,3-hepta-fluoro-7,7-dimethyloctane-4,6-dione) have been determined. The metal coordination spheres in compounds 1 and 2 are essentially the same as the respective M(acac)₃ derivatives. Despite the isomorphous nature of the structures of compounds 1 and 2, the identity of the nearest intermolecular van der Waals contacts are altered by minor changes in the metal coordination sphere. The geometry about copper in compound 3 is close to that of an ideal square bipyramid with the -diketonate ligands occupying the basal plane. The water ligand in each molecule of compound 3 is hydrogen bonded to an oxygen of a -diketonate ligand on an adjacent molecule resulting in the formation of dimers, which form rods along the y-axis due to weak C–F···Cu interactions. Crystal data: (1) orthorhombic, Pca2₁, a = 14.949(3), b = 19.806(4), c = 13.624(3) Å, V = 4033(1) ų, and Z = 8, and (2) orthorhombic, Pca2₁, a = 14.930(3), b = 19.620(4), c = 13.540(3) Å, V = 3966(1) ų, and Z = 8,; (3) monoclinic, P2₁/c, a = 12.447(3), b = 10.486(2) c = 21.980(4) Å, = 102.65(3)°, V = 2799(1) ų, and Z = 4.     

Crystal and molecular structures of 1-(2-ethyloxycarbonylo propan-2-ylamino)-3-(1-napthyloxy) propan-2-ol-hydrochloride (1) (C19H26NO4Cl) and 1-(2-isopropyloxycarbonylo-propan-2-ylamino)-3-(1-napthyloxy) propan-2-ol hydrochloride (2) (C20H28N04Cl)

The crystal structures of two new-adrenergic antagonists, derivatives of propranolol, are shown in this paper. The space groups and unit-cell parameters are: compound1 (C₁₉H₂₆NO₄Cl): triclinic, space groupP1,a=6.420(1),b=10.161(1),c=15.823(1) Å,=82.47(1),=84.16(1), =77.55(1)°; compound 2 (C₂₀H₂₈NO₄Cl): monoclinic, space groupP2₁/c,a=6.460(1),b=33.285(2),c=10.120(1) Å,=104.83(1)°. The structures were solved by direct methods and refined with full-matrix least-squares techniques toR indices of 0.055 and 0.048, respectively. The –CH(OH)-CH₂-NH-sections of the side chains show the conformation approximate togauche.