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author:("Saeed, kamer")
1.  9-(2-Hy­droxy-6-oxocyclo­hex-1-en-1-yl)-2,3,4,9-tetra­hydro-1H-xanthen-1-one 
In the xanthene ring system in the title compound, C19H18O4, the 4H-pyran ring has a maximum deviation of 0.110 (2) Å from planarity and the cyclo­hexene ring exhibits a puckered conformation [puckering parameters Q T = 0.452 (3) Å, θ = 57.0 (4) and ϕ = 131.7 (4)°]. The cyclo­hexene ring attached to the xanthene system adopts an envelope conformation, with the middle of the three methylene C atoms as the flap atom. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds form infinite chains of R 1 2(6) ring motifs along [100] with the xanthene groups arranged in an alternating zigzag manner.
PMCID: PMC3629652  PMID: 23634139
2.  Methyl 2-oxo-2H-chromene-3-carboxyl­ate 
The title compound, C11H8O4, features an almost planar mol­ecule (r.m.s. deviation = 0.033 Å for all non-H atoms). In the crystal, the mol­ecules are linked via C—H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to (1-21).
PMCID: PMC3470378  PMID: 23125791
3.  Pharmacological Evaluation and Docking Studies of 3-Thiadiazolyl- and Thioxo-1,2,4-triazolylcoumarin Derivatives as Cholinesterase Inhibitors 
ISRN Pharmacology  2012;2012:707932.
Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is considered a promising strategy for the treatment of Alzheimer's disease (AD). This research project aims to provide a comprehensive knowledge of newly synthesized coumarin analogues with anti-AD potential. In the present work a series of 3-thiadiazolyl- and thioxo-1,2,4-triazolylcoumarins derivatives were designed, synthesized, and tested as potent inhibitors of cholinesterases. These compounds were assayed against AChE from electrophorus electricus and rabbit; and BChE from horse serum and rabbit by Ellman's method using neostigmine methylsulphate and donepezil as reference drugs. Some of the assayed compounds proved to be potent inhibitors of AChE and BChE with Ki values in the micromolar range. 4b was found to be the most active compound with Ki value 0.028 ± 0.002 μM and higher selectivity for AChE/BChE. The ability of 4b to interact with AChE was further confirmed through computational studies, in which a primary binding was proved to occur at the active gorge site, and a secondary binding was revealed at the peripheral anionic site. Structure activity relationships of prepared compounds were also discussed.
PMCID: PMC3431135  PMID: 22966467
4.  N′-(2,4-Dinitro­phen­yl)benzohydrazide 
In the title compound, C13H10N4O5, the aromatic ring planes are close to perpendicular [dihedral angle = 75.94 (5)°] and the C—N—N—C torsion angle is 88.7 (2)°. Both nitro groups lie close to their attached ring plane, with C—C—N—O torsion angles of 3.1 (2) and 5.3 (2)°. This allows for the formation of an intra­molecular N—H⋯O hydrogen bond, which closes an S(6) ring. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into zigzag chains extending along [100].
PMCID: PMC3414336  PMID: 22904869
5.  6-Meth­oxy-1,3-benzothia­zol-2-amine 
The title compound, C8H8N2OS, is almost planar, the C—C—O—C torsion angle associated with the meth­oxy group being 0.72 (1)°. Inter­molecular amine N—H⋯N hydrogen-bonding inter­actions form inversion dimers [graph set R 2 2(8)] which are extended into chains along the b axis through amine N—H⋯O hydrogen bonds.
PMCID: PMC3394031  PMID: 22798896
6.  Space group revsion of the triclinic polymorph of salicyl­aldehyde azine 
The structure of the title compound, C14H12N2O2 {systematic name: 2,2′-[hydrazinediylidenebis(methanylyl­idene)]diphen­ol}, has already been determined in the triclinic space group P with Z = 4 [El-Medani, Aboaly, Abdalla & Ramadan (2004 ▶). Spectrosc. Lett. 37, 619–632]. However, the correct space group should be P21/c with Z = 4. This structure is a new polymorph of the already known monoclinic polymorph of salicyladehyde azine, which crystallizes in space group P21/n with Z = 2. The benzene rings form a dihedral angle of 46.12 (9)°. Two intramolucular O—H⋯N hydrogen bonds occur.
PMCID: PMC3274948  PMID: 22346901
7.  (E)-1-(4-Chloro­benzyl­idene)thio­semi­carbazide 
In the crystal of the title compound, C8H8ClN3S, mol­ecules are connected by N—H⋯S hydrogen bonds into strips parallel to the (112) planes and running along [10]. One of the amino H atoms is not involved in a classical hydrogen bond. In addition, there is a rather short inter­molecular Cl⋯S distance of 3.3814 (5) Å.
PMCID: PMC3052038  PMID: 21522401
8.  2-Chloro-N-(4-meth­oxy­phen­yl)benzamide 
In the title compound, C14H12ClNO2, the chloro- and meth­oxy-substituted benzene rings are close to orthogonal [dihedral angle = 79.20 (3)°]. These rings also make angles of 45.9 (3) and 33.5 (3)° with the amide –CONH– unit. The meth­oxy substituent lies close to the meth­oxy­benzene ring plane, with a maximum deviation of 0.142 (3) Å for the methyl C atom. The N—H bond is anti to the 2-chloro substituent of the aniline ring. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds form C(4) chains augmented by a weak C—H⋯O inter­action involving an ortho H atom of the meth­oxy benzene ring that generates an R 2 1(6) motif. The chains stack the mol­ecules into columns down the b axis. Adjacent columns are linked by additional C—H⋯O and C—H⋯π contacts, generating a three-dimensional network.
PMCID: PMC3009019  PMID: 21589131
9.  A monoclinic polymorph of N-(3-chloro­phen­yl)benzamide 
The title compound, C13H10ClNO, (I), is a polymorph of the structure, (II), first reported by Gowda et al. [Acta Cryst. (2008), E64, o462]. In the original report, the compound crystallized in the ortho­rhom­bic space group Pbca (Z = 8), whereas the structure reported here is monoclinic P21/c (Z = 4). The principal difference between the two forms lies in the relative orientations of the phenyl and benzene rings [dihedral angle = 8.90 (13)° for (I) and 61.0 (1)° for (II)]. The inclination of the amide –CONH– units to the benzoyl ring is more similar [15.8 (7)° for (I) and 18.2 (2)° for (II)]. In both forms, the N—H bonds are anti to the 3-chloro substituents of the aniline rings. In the crystal, inter­molecular N—H⋯O hydrogen bonds form C(4) chains along c. These chains are bolstered by weak C—H⋯O inter­actions that generate R 2 1(6) and R 2 1(7) ring motifs.
PMCID: PMC3008970  PMID: 21589001
10.  1,1′-(9-Octyl-9H-carbazole-3,6-di­yl)diethanone 
The central structural element of the title compound, C24H29NO2, is a carbazole unit substituted with two acetyl residues and an octyl chain. The acetyl residues are nearly coplanar [dihedral angles = 5.37 (14) and 1.0 (3)°] with the carbazole unit which is essentially planar (r.m.s. deviation for all non-H atoms = 0.025 Å). The octyl chain adopts an all-trans conformation. The crystal packing is stabilized by C—H⋯O hydrogen bonds.
PMCID: PMC3007423  PMID: 21588408
11.  5-(3,4,5-Trimeth­oxy­phen­yl)-1,3,4-oxadiazole-2(3H)-thione 
The two rings in the title compound, C11H12N2O4S, are roughly coplanar [dihedral angle = 6.77 (8)°]. Whereas the two outer methyl groups of the three meth­oxy groups are almost coplanar with the aromatic ring to which they are attached [C—C—O—C torsion angles = 8.5 (3) and −8.3 (3)°], the methyl group of the central meth­oxy substituent is not [C—C—C—C = −78.4 (3)°]. The crystal packing is stabilized by N—H⋯O hydrogen bonding.
PMCID: PMC3007562  PMID: 21588243
12.  1-(4-Fluoro­phen­yl)thio­urea 
In the title compound, C7H7FN2S, the aromatic ring plane and the thio­urea unit are twisted with a torsion angle C—C—N—C7 of 44.6 (2)°. In the crystal, N—H⋯S and N—H⋯F inter­molecular hydrogen bonds link the mol­ecules into infinite sheets that are stacked along the c axis.
PMCID: PMC3006870  PMID: 21587802
13.  1-(2-Fluoro­phen­yl)-3-(3,4,5-trimethoxy­benzo­yl)thio­urea 
The two m-meth­oxy groups of the title compound, C17H17FN2O4S, are almost coplanar with the aromatic ring [CH3—O—C—C = 5.8 (1) and 5.9 (1)°], whereas the meth­oxy group in the para position is bent out of the ring plane [78.6 (1)°]. Mol­ecules are connected by inter­molecular N—H⋯S hydrogen bonds to form centrosymmetric dimers that are stacked along the a axis.
PMCID: PMC2979251  PMID: 21579182
14.  Methyl 3,5-dibromo-4-methyl­benzoate 
In the title compound, C9H8Br2O2, the mol­ecule is essentially planar with an r.m.s. deviation of 0.0652 Å from the mean plane through all non-H atoms and a dihedral angle of 7.1 (2)° between the benzene ring plane and the carboxyl­ate substituent. In the crystal structure, weak C—H⋯Br hydrogen bonds and weak inter­molecular O⋯Br contacts [3.095 (2) Å], link adjacent mol­ecules into layers parallel to (102). Additional weak inter­molecular C—H⋯O hydrogen bond inter­actions stack the layers above and below the mol­ecular plane and down the a axis.
PMCID: PMC2983755  PMID: 21580779
15.  (Biphenyl-4-yl)(phen­yl)methanone 
In the title compound, C19H14O, the dihedral angle between the two aromatic rings of the biphenyl residue is 8.0 (3)° and the dihedral angle between the two rings connected by the carbonyl C atom is 51.74 (18)°. There are no short C—H⋯O contacts in the crystal structure.
PMCID: PMC2983880  PMID: 21580736
16.  2-Methyl-N-p-tolyl­benzamide: a second monoclinic polymorph 
The title compound, C15H15NO, (I), is a polymorph of the structure (II) reported by Gowda et al. [Acta Cryst. (2008), E64, o1494]. Compound (II) crystalllizes in the space group C2/c (Z = 8), whereas the title compound occurs in space group P21/c (Z = 4). The two mol­ecular structures differ slightly in the relative orientations of their central amide group with respect to the benzoyl ring [dihedral angles of 55.99 (7) for (I) and 59.96 (11)° for (II)] and in the inclination of the benzoyl and aniline rings [88.67 (8) for (I) and 81.44 (5)° for (II)]. In the crystal structure of (I), mol­ecules are linked by N—H⋯O hydrogen bonds, forming C(4) chains, which are augmented by weak C—H⋯O inter­actions. The structure is further stabilized by C—H⋯π contacts involving both of the aromatic rings.
PMCID: PMC2983768  PMID: 21580722
17.  4,4,6-Trimethyl-1-(3-methyl­phen­yl)-3,4-dihydro­pyrimidine-2(1H)-thione 
The asymmetric unit of the title compound, C14H18N2S, contains two independent and conformationally similar mol­ecules, which form cyclic dimers via inter­molecular hydrogen bonds of the type N—H⋯S [graph set R 2 2(8)]. The structure is iso­morphous with that of one of the polymorphs of 4,4,6-tri­methyl-1-phenyl-3,4-dihydro­pyrimidine-2(1H)-thione [Yam­in et al. (2005 ▶). Acta Cryst. E61, o55–o57].
PMCID: PMC2983710  PMID: 21580391
18.  N-(2-Fluoro­phen­yl)cinnamamide 
The title compound, C15H12FNO, was prepared by the reaction of cinnamoyl chloride with 4-fluoro­aniline and crystallizes with two mol­ecules A and B in the asymmetric unit. The two unique mol­ecules are closely similar and overlay with an r.m.s. deviation of 0.0819 Å. The fluoro­benzene and phenyl rings are inclined to one another at 73.89 (7) and 79.46 (7)°, respectively, in mol­ecules A and B. The amide C—N—C(O)—C portions of the mol­ecules are planar (r.m.s. deviations = 0.035 and 0.028 Å) and are inclined at 45.51 (9) and 47.71 (9), respectively, to the fluoro­benzene rings in mol­ecules A and B. The 2-fluoro­acetamide units and the benzene rings each adopt E configurations with respect to the C=C bonds. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds augmented by weak C—H⋯π inter­actions link mol­ecules into rows in a head-to-tail fashion along a. Additional weak C—H⋯O contacts further stabilize the packing, forming a three-dimensional network stacked down a.
PMCID: PMC2983731  PMID: 21580305
19.  1-(4-Chloro­phen­yl)-4,4,6-trimethyl-3,4-dihydro­pyrimidine-2(1H)-thione 
The dihydro­pyrimidine ring of the title compound, C13H15ClN2S, adopts an envelope conformation with five almost coplanar atoms (r.m.s. deviation = 0.054 Å) and the C atom bearing the two methyl substituents deviating from this plane by 0.441 (2) Å. The best plane through the five almost coplanar atoms forms a dihedral angle of 89.56 (5)° with the benzene ring. The crystal packing is characterized by centrosymmetric dimers connected by pairs of N—H⋯S hydrogen bonds.
PMCID: PMC2979773  PMID: 21579855
20.  3,3′-Dibutanoyl-1,1′-(o-phenyl­ene)dithio­urea 
The mol­ecular conformation of the title compound, C16H22N4O2S2, is stabilized by two intramolecular N—H⋯O hydrogen bonds. The crystal packing shows N—H⋯O and N—H⋯S hydrogen bonds.
PMCID: PMC2979833  PMID: 21579856
21.  4-Chloro-N-(2-methoxy­phen­yl)benzamide 
The title compound, C14H12ClNO2, was prepared by refluxing 4-chloro­benzoyl chloride with o-anisidine in CHCl3. The methoxy­phen­yl–amide segment of the mol­ecule is almost planar, with a dihedral angle of 5.10 (7)° between the benzene ring and the C—N—C(O)—C fragment. A weak intra­molecular N—H⋯O contact forms an S(5) ring and contributes to the planarity of this portion of the mol­ecule. The two benzene rings are inclined at an angle of 26.74 (7)°. In the crystal structure, inter­molecular Cl⋯O inter­actions of 3.1874 (9) Å generate centrosymmetric dimers. These are further linked by C—H⋯O and C—H⋯π inter­actions, forming inversion related sheets parallel to [001].
PMCID: PMC2980066  PMID: 21580098
22.  2-Methyl-N-o-tolyl­benzamide 
In the title compound, C15H15NO, the C—N—C(O)—C amide unit is planar (r.m.s. deviation = 0.003 Å) and subtends dihedral angles of 44.71 (5) and 43.33 (5)° with the two o-tolyl rings. These aromatic rings are inclined at 4.94 (7)° to one another. The ortho-methyl groups of the two tolyl rings are anti to one another. In the crystal structure, N—H⋯O hydrogen bonds augmented by C—H⋯π inter­actions link the mol­ecules in a head-to-head fashion into chains along a. Independent chains pack in a herringbone pattern along c.
PMCID: PMC2980266  PMID: 21580074
23.  N-Cyclo­hexyl-3,4,5-trimethoxy­benzamide 
The 3,5-meth­oxy groups in the title compound, C16H23NO4, are almost coplanar with the aromatic ring, whereas the 4-meth­oxy group is bent out of this plane. The three CH3—O—C—C torsion angles are −1.51 (18), 0.73 (19) and 75.33 (15)°. The cyclo­hexane ring adopts a chair conformation. In the crystal, mol­ecules are connected by inter­molecular N—H⋯O hydrogen bonds into chains running along the b axis.
PMCID: PMC2972029  PMID: 21578939
24.  Ethyl 4-[3-(2-methyl­benzo­yl)thio­ureido]benzoate 
The mol­ecular conformation of the title compound, C18H18N2O3S, is stabilized by an intra­molecular N—H⋯O hydrogen bond. The crystal packing shows centrosymmetric dimers connected by N—H⋯S hydrogen bonds. The terminal eth­oxy substituents are statistically disordered [occupancy ratio 0.527 (5):0.473 (5)].
PMCID: PMC2970993  PMID: 21578367
25.  2,4-Dichloro-N-p-tolyl­benzamide 
In the title compound, C14H11Cl2NO, the C—N—C(=O)—C amide unit is almost planar (r.m.s. deviation = 0.0317 Å) and subtends dihedral angles of 65.93 (6) and 29.45 (7)°, respectively, to the dichloro­benzene and tolyl rings. The two aromatic rings are inclined at 37.92 (6)° to one another. In the crystal structure, N—H⋯O hydrogen bonds link the mol­ecules into chains along b. Additional weak C—H⋯Cl and C—H⋯O hydrogen bonds combine with C—H⋯π and very weak π–π contacts [Cg⋯Cg distance = 4.0217 (12) Å] to stack the mol­ecules down b.
PMCID: PMC2970402  PMID: 21577972

Results 1-25 (57)