Browsing by Author "Ooi, C.W."

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2-(4-Bromophenyl)-2-oxoethyl 2-methylbenzoate
(2011) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Isloor, A.M.; Satyanarayan, M.N.
In the title compound, C16H13BrO3, the dihedral angle formed between the bromo- and methyl-substituted benzene rings is 66.66 (8) . In the crystal, molecules are linked by inter-molecular C - H?O hydrogen bonds, forming a two-dimensional network parallel to the ac plane. The crystal packing is further consolidated by C - H?? interactions. Fun et al. 2011.
2-(4-Bromophenyl)-2-oxoethyl 2-methylbenzoate
(2011) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Isloor, A.M.; Satyanarayan, M.N.
In the title compound, C16H13BrO3, the dihedral angle formed between the bromo- and methyl-substituted benzene rings is 66.66 (8)°. In the crystal, molecules are linked by inter-molecular C - H?O hydrogen bonds, forming a two-dimensional network parallel to the ac plane. The crystal packing is further consolidated by C - H?? interactions. © Fun et al. 2011.
2-[(E)-4-Diethylamino-2-hydroxybenzyl-idene]hydrazinecarboxamide
(2012) Fun, H.-K.; Ooi, C.W.; Malladi, S.; Isloor, A.M.; Shivananda, K.N.
Two molecules make up the asymmetric unit of the title compound, C 12H 18N 4O 2, and both feature an intramolecular O - H?N hydrogen bond, which generates an S(6) ring. The diethylamino group of one of the molecules is disordered over two sets of sites in a 0.59 (2):0.41 (2) ratio. In the crystal, N - H?O hydrogen bonds link the molecules into sheets lying parallel to the ac plane and C - H?? interactions are also observed.
2-[(E)-4-Diethylamino-2-hydroxybenzyl-idene]hydrazinecarboxamide
(2012) Fun, H.-K.; Ooi, C.W.; Malladi, S.; Isloor, A.M.; Shivananda, K.N.
Two molecules make up the asymmetric unit of the title compound, C 12H 18N 4O 2, and both feature an intramolecular O - H?N hydrogen bond, which generates an S(6) ring. The diethylamino group of one of the molecules is disordered over two sets of sites in a 0.59 (2):0.41 (2) ratio. In the crystal, N - H?O hydrogen bonds link the molecules into sheets lying parallel to the ac plane and C - H?? interactions are also observed.
4-(4-Bromophenyl)-1-(2,6-difluorobenzyl)-3-(3,4,5-trimethoxyphenyl)-1H-1,2, 4-triazole-5(4H)-thione
(2012) Fun, H.-K.; Ooi, C.W.; Chandrakantha, B.; Isloor, A.M.; Shetty, P.
In the title compound, C 24H 20BrF 2N 3O 3S, the triazole ring (r.m.s. deviation = 0.0107 ) makes dihedral angles of 28.18(14), 63.76(14) and 77.01(18) , respectively, with the trimethoxy-, bromo-, and difluoro-substituted benzene rings. The C atoms of the meta methoxy groups are roughly coplanar with their ring [displacements =-0.289(4) and 0.083(7) ], whereas the C atom of the para group is displaced [1.117(3) ]. In the crystal, inversion dimers linked by two pairs of C-H O hydrogen bonds occur. The ring motif of the two hydrogen bonds to their symmetry-generated O-atom acceptors is R 2 2(8).
4-(4-Bromophenyl)-1-(2,6-difluorobenzyl)-3-(3,4,5-trimethoxyphenyl)-1H-1,2, 4-triazole-5(4H)-thione
(2012) Fun, H.-K.; Ooi, C.W.; Chandrakantha, B.; Isloor, A.M.; Shetty, P.
In the title compound, C 24H 20BrF 2N 3O 3S, the triazole ring (r.m.s. deviation = 0.0107 Å) makes dihedral angles of 28.18(14), 63.76(14) and 77.01(18)°, respectively, with the trimethoxy-, bromo-, and difluoro-substituted benzene rings. The C atoms of the meta methoxy groups are roughly coplanar with their ring [displacements =-0.289(4) and 0.083(7) Å], whereas the C atom of the para group is displaced [1.117(3) Å]. In the crystal, inversion dimers linked by two pairs of C-H··· O hydrogen bonds occur. The ring motif of the two hydrogen bonds to their symmetry-generated O-atom acceptors is R 2 2(8).
Diethyl 2,6-dimethyl-4-(5-phenyl-1H-pyrazol-4-yl)-1,4-dihydropyridine-3,5- dicarboxylate
(2012) Fun, H.-K.; Ooi, C.W.; Malladi, S.; Shivananda, K.N.; Isloor, A.M.
In the title compound, C 22H 25N 3O 4, the dihydro-pyridine ring adopts a flattened boat conformation. The pyrazole ring makes a dihedral angle of 29.04 (5) with the benzene ring. The mol-ecular structure is stabilized by an intra-molecular C - H?O hydrogen bond which generates an S(9) ring motif. In the crystal, molecules are linked via N - H?O and C - H?N hydrogen bonds into a two-dimensional network parallel to the ab plane. The crystal structure is further consolidated by weak C - H?? inter-actions.
Diethyl 2,6-dimethyl-4-(5-phenyl-1H-pyrazol-4-yl)-1,4-dihydropyridine-3,5- dicarboxylate
(2012) Fun, H.-K.; Ooi, C.W.; Malladi, S.; Shivananda, K.N.; Isloor, A.M.
In the title compound, C 22H 25N 3O 4, the dihydro-pyridine ring adopts a flattened boat conformation. The pyrazole ring makes a dihedral angle of 29.04 (5)° with the benzene ring. The mol-ecular structure is stabilized by an intra-molecular C - H?O hydrogen bond which generates an S(9) ring motif. In the crystal, molecules are linked via N - H?O and C - H?N hydrogen bonds into a two-dimensional network parallel to the ab plane. The crystal structure is further consolidated by weak C - H?? inter-actions.
Dimethyl 4-[3-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-4-yl]-2,6-dimethyl-1,4- dihydro-pyridine-3,5-dicarboxylate dihydrate
(2012) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Shivananda, K.N.; Isloor, A.M.
In the title compound, C27H27N3O5 2H2O, the dihydro-pyridine ring adopts a flattened boat conformation. The central pyrazole ring is essentially planar [maximum deviation of 0.003 (1) ] and makes dihedral angles of 50.42 (6) and 26.44 (6) with the benzene rings. In the crystal, molecules are linked via N - H?O, O - H?O, O - H?N and C - H?O hydrogen bonds into two-dimensional networks parallel to the bc plane. The crystal structure is further consolidated by weak C - H?? interactions. 2012 International Union of Crystallography.
Dimethyl 4-[3-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-4-yl]-2,6-dimethyl-1,4- dihydro-pyridine-3,5-dicarboxylate dihydrate
(2012) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Shivananda, K.N.; Isloor, A.M.
In the title compound, C27H27N3O5· 2H2O, the dihydro-pyridine ring adopts a flattened boat conformation. The central pyrazole ring is essentially planar [maximum deviation of 0.003 (1) Å] and makes dihedral angles of 50.42 (6) and 26.44 (6)°with the benzene rings. In the crystal, molecules are linked via N - H?O, O - H?O, O - H?N and C - H?O hydrogen bonds into two-dimensional networks parallel to the bc plane. The crystal structure is further consolidated by weak C - H?? interactions. © 2012 International Union of Crystallography.
Ethyl 1-(2,4-dichlorobenzyl)-4-oxo-7-trifluoromethyl-1,4-dihydroquinoline- 3-carboxyl-ate
(2012) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Isloor, A.M.; Hegde, G.
In the title compound, C 20H 14Cl 2F 3NO 3, the trifluromethyl group is disordered over two sets of sites in a 0.784 (10):0.216 (10) ratio. The quinoline ring system is essentially planar with a maximum deviation of 0.058 (2) for the N atom and forms dihedral angles of 89.23 (11) and 8.13 (17) , respectively with the mean planes of the benzene ring and the carboxylate group. In the crystal, pairs of weak C - H?O and C - H?F hydrogen bonds link molecules into centrosymmetric dimers. The crystal structure is further stabilized by weak ?-? [centroid-centroid distance = 3.624 (2) ] interactions.
Ethyl 1-(2,4-dichlorobenzyl)-4-oxo-7-trifluoromethyl-1,4-dihydroquinoline- 3-carboxyl-ate
(2012) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Isloor, A.M.; Hegde, G.
In the title compound, C 20H 14Cl 2F 3NO 3, the trifluromethyl group is disordered over two sets of sites in a 0.784 (10):0.216 (10) ratio. The quinoline ring system is essentially planar with a maximum deviation of 0.058 (2) Å for the N atom and forms dihedral angles of 89.23 (11) and 8.13 (17)°, respectively with the mean planes of the benzene ring and the carboxylate group. In the crystal, pairs of weak C - H?O and C - H?F hydrogen bonds link molecules into centrosymmetric dimers. The crystal structure is further stabilized by weak ?-? [centroid-centroid distance = 3.624 (2) Å] interactions.
Ethyl 4-{[1-(2,4-dichlorobenzyl)-1 H- 1,2,3-triazol-4-yl]methoxy}-8- (trifluoro-methyl) quinoline-3-carboxylate
(2012) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Isloor, A.M.; Rashid, S.A.
In the title compound, C23H17Cl2F 3N4O3, the triazole ring makes dihedral angles of 50.27 (6) and 82.78 (7) with the quinoline ring system and the dichloro-substituted benzene ring. The dihedral angle between the quinoline and dichloro-substituted benzene rings is 38.17 (4) . In the crystal, molecules are linked via C - H N, C - H F and C - H O hydrogen bonds into a three-dimensional network. The crystal is further consolidated by C - H ? contacts to the triazole ring and inversion-related ?-? interactions between the benzene and pyridine rings of quinoline systems [centroid-centroid distance = 3.7037 (7) ].
Ethyl 4-{[1-(2,4-dichlorobenzyl)-1 H- 1,2,3-triazol-4-yl]methoxy}-8- (trifluoro-methyl) quinoline-3-carboxylate
(2012) Fun, H.-K.; Ooi, C.W.; Garudachari, B.; Isloor, A.M.; Abdul Rashid, S.A.
In the title compound, C23H17Cl2F 3N4O3, the triazole ring makes dihedral angles of 50.27 (6) and 82.78 (7)° with the quinoline ring system and the dichloro-substituted benzene ring. The dihedral angle between the quinoline and dichloro-substituted benzene rings is 38.17 (4)°. In the crystal, molecules are linked via C - H·N, C - H·F and C - H·O hydrogen bonds into a three-dimensional network. The crystal is further consolidated by C - H·? contacts to the triazole ring and inversion-related ?-? interactions between the benzene and pyridine rings of quinoline systems [centroid-centroid distance = 3.7037 (7) Å].
Syntheses, crystal structures and antimicrobial studies of two new semicarbazone derivatives
(2014) Chia, T.S.; Quah, C.K.; Ooi, C.W.; Garudachari, B.; Isloor, N.A.; Isloor, A.M.; Fun, H.-K.
Two new derivatives of semicarbazone, (E)-2-(hexan-2-ylidene) hydrazinecarboxamide and (E)-2-(heptan-2-ylidene)hydrazinecarboxamide were synthesized and characterized by IR and 1H NMR. Their crystal structures were characterized by X-ray diffraction method. Compound (I) crystallizes in triclinic P 1 ?, a = 6.7679(7) , b = 7.1912(8) , c = 9.9969(11) , ? = 108.824(2), ? = 99.398(3), ? = 92.680(2), V = 451.75(8) 3, Z = 2, R 1 = 0.043 and wR 2 = 0.140. Compound (II) crystallizes in triclinic P 1 ?, a = 6.7192(6) , b = 7.2094(6) , c = 11.2842(11) , ? = 103.303(2), ? = 106.198(2), ? = 91.219(1), V = 508.70(8) 3, Z = 2, R 1 = 0.044 and wR 2 = 0.133. Their molecules adopt a L-shape conformation with C atom in C=N double bond acting as the junction point. The C=O double bond indicate the existence of semicarbazone group in keto-like form for both compounds in their solid state. In the crystal, the carbonyl O atom for both derivatives acts as a common acceptor in the intermolecular bifurcated N-H O hydrogen bonding which linked the molecules into one-dimensional supramolecular ribbons. Antimicrobial studies by serial dilution method showed both compounds exhibit antibacterial property. Graphical Abstract: Two new semicarbazone derivatives are characterized by IR, 1H NMR and single crystal X-ray diffraction methods and their antibacterial activity was further investigated by screening against four different bacterial strains.[Figure not available: see fulltext.] 2013 Springer Science+Business Media New York.
Syntheses, crystal structures and antimicrobial studies of two new semicarbazone derivatives
(2014) Chia, T.S.; Ching Kheng, C.K.; Ooi, C.W.; Garudachari, B.; Isloor, N.A.; Isloor, A.M.; Fun, H.-K.
Two new derivatives of semicarbazone, (E)-2-(hexan-2-ylidene) hydrazinecarboxamide and (E)-2-(heptan-2-ylidene)hydrazinecarboxamide were synthesized and characterized by IR and 1H NMR. Their crystal structures were characterized by X-ray diffraction method. Compound (I) crystallizes in triclinic P 1 ?, a = 6.7679(7) Å, b = 7.1912(8) Å, c = 9.9969(11) Å, ? = 108.824(2), ? = 99.398(3), ? = 92.680(2), V = 451.75(8) Å3, Z = 2, R 1 = 0.043 and wR 2 = 0.140. Compound (II) crystallizes in triclinic P 1 ?, a = 6.7192(6) Å, b = 7.2094(6) Å, c = 11.2842(11) Å, ? = 103.303(2), ? = 106.198(2), ? = 91.219(1), V = 508.70(8) Å3, Z = 2, R 1 = 0.044 and wR 2 = 0.133. Their molecules adopt a L-shape conformation with C atom in C=N double bond acting as the junction point. The C=O double bond indicate the existence of semicarbazone group in keto-like form for both compounds in their solid state. In the crystal, the carbonyl O atom for both derivatives acts as a common acceptor in the intermolecular bifurcated N-H·O hydrogen bonding which linked the molecules into one-dimensional supramolecular ribbons. Antimicrobial studies by serial dilution method showed both compounds exhibit antibacterial property. Graphical Abstract: Two new semicarbazone derivatives are characterized by IR, 1H NMR and single crystal X-ray diffraction methods and their antibacterial activity was further investigated by screening against four different bacterial strains.[Figure not available: see fulltext.] © 2013 Springer Science+Business Media New York.