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1.  2,2′-[(4-Methyl-2-phenyl­imidazolidine-1,3-di­yl)bis­(methyl­ene)]diphenol 
The methyl-substituted imidazolidine ring of the title compound, C24H26N2O2, adopts an envelope conformation with the N atom adjacent to the methyl­ene group as the flap. The meth­yl–ethyl­ene fragment in this ring is disordered over two positions with an occupancy ratio of 0.899 (4):0.101 (4). The hy­droxy­benzyl groups are inclined at 71.57 (15) and 69.97 (19)° to the mean plane of major disorder component of the heterocyclic ring with an inter­planar angle between the two hy­droxy­benzyl groups of 66.00 (5)°. The phenyl substit­uent approaches a nearly perpendicular orientation relative to the mean plane of the imidazolidine ring, making a dihedral angle of 75.60 (12)°. This conformation is stabilized by two intra­molecular O—H⋯N bonds, which generate S(6) ring motifs.
PMCID: PMC3793710  PMID: 24109297
2.  Single-step synthesis of a new series of meso di-Mannich bases from the cyclic aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[,170.2,7011,16]icosane and p-substituted phenols 
The results presented herein show that the cyclic aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[,170.2,7011,16]icosane (6), derived from cis-(meso)-1,2-diaminocyclohexane and formaldehyde, is a suitable substrate for the preption of a series of cis-meso Mannich bases such as 8a-l by reaction with p-substituted phenols 7a-l in basic media. These compounds are valuable synthetic products and may find application in asymmetric catalysis.
The products were characterized principally by NMR and IR spectroscopy. Both the benzylic and aminalic protons of the perhydrobenzimidazolidine moiety were diastereotopic due to the presence of stereogenic nitrogen centers. The occurrence of intramolecular hydrogen bonding interactions was confirmed by the broad OH stretching vibration band in the IR spectra. Vibrational spectra were calculated using B3LYP at 6-31G(d,p) level, and the calculated frequencies for the νOH vibrations were compared to those of the experimental spectra. Hydrogen bonding interactions in the solid state were observed through the X-ray crystallography of 8j. Additionally, Mulliken charges and Fukui indices for 6 were calculated as theoretical descriptors of electrophilicity.
A new series of meso Mannich bases called 4,4′-disubstituted-2,2′-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene)} diphenols (8a-l) which are derived from cis-(meso)-1,2-diaminocyclohexane, were obtained from cyclic aminal 6. These results confirmed the behavior of 6 as an electrophilic preformed reagent in Mannich reactions in basic media.
PMCID: PMC3698105  PMID: 23758899
3.  1,3-Dibenzyl-2-(2-chloro­phen­yl)-4-methyl­imidazolidine 
In the title compound, C24H25ClN2, the methine, methyl­ene and methyl C atoms of the methyl-substituted imidazolidine ring are disordered over two sets of sites with a refined occupancy ratio of 0.834 (4):0.166 (4). Each disordered ring assumes an envelope conformation with an N atom as the flap. The pendant benzyl rings are oriented equatorially with respect to the imidazolidine ring. The chloro­phenyl ring is inclined to the mean plane of the four planar atoms of the major component of the imidazolidine ring by 76.27 (12)°. The dihedral angles between the chloro­phenyl ring and the two benzyl rings are 55.31 (9) and 57.50 (8)°; the dihedral angle between these latter rings is 71.59 (9)°. In the crystal, mol­ecules are linked by C—H⋯Cl inter­actions and a number of weak C—H⋯π inter­actions, involving all three aromatic rings, forming a three-dimensional structure.
PMCID: PMC3589010  PMID: 23476246
4.  (2S,7S)-10-Ethyl-1,8,10,12-tetra­aza­tetra­cyclo­[,12.02,7]penta­decan-10-ium iodide 
The title chiral quaternary ammonium salt, C13H25N4 +·I−, was synthesized through the Menschutkin reaction between the cage aminal (2S,7S)-1,8,10,12-tetra­aza­tetra­cyclo­[,12.02,7]penta­decane and ethyl iodide. The quaternization occurred regioselectively on the nitrogen with major sp3 character. The crystal structure consists of anions and cations separated by normal distances. Ions are not linked through C—H⋯I hydrogen bonds.
PMCID: PMC3470393  PMID: 23125806
5.  [μ-N,N′-Bis(2-amino­eth­yl)ethane-1,2-diamine-κ4 N 1,N 1′:N 2,N 2′]bis­{[N,N′-bis­(2-amino­eth­yl)ethane-1,2-diamine-κ4 N,N′,N′′,N′′′]cadmium} tetra­kis­(perchlorate) 
The centrosymmetric dinuclear cadmium title complex, [Cd2(C6H18N4)3](ClO4)4, was obtained by the reaction of N,N′-bis­(2-amino­eth­yl)ethane-1,2-diamine (trien) with Cd(NO3)2·4H2O and sodium perchlorate in methanol. The CdII cation is coordinated by four N atoms of a non-bridging trien ligand and by two N atoms of a bridging trien ligand in a slightly distorted octa­hedral coordination geometry. The bridging ligand shares another two N atoms with a neighboring symmetry-equivalent CdII cation. The structure displays C—H⋯O and N—H⋯O hydrogen bonding. The perchlorate anion is disordered over two sets of sites in a 0.854 (7): 0.146 (7) ratio.
PMCID: PMC3435582  PMID: 22969455
6.  Bis[N-(3-amino­prop­yl)propane-1,3-di­amine-κ3 N,N′,N′′]cadmium nitrate perchlorate 
The title complex, [Cd(C6H17N3)2](ClO4)(NO3), was synthesized by the reaction of Cd(NO3)2·4H2O, bis­(3-amino­prop­yl)­amine and sodium perchlorate in methanol. The asymmetric unit of the title complex consists of one Cd2+ cation, two tridentate bis­(3-amino­prop­yl)amine ligands, one nitrate anion and one perchlorate anion. The Cd2+ cation is coordinated by six N atoms of the bis­(3-amino­prop­yl)amine ligands in a slightly distorted octa­hedral coordination geometry. In the crystal, mol­ecules are held together by an intricate network of N—H⋯O inter­actions. One of the two amine ligands was found to be disordered over two sets of sites, with a ratio of 0.802 (3):0.198 (3), similarly to the nitrate anion, with a ratio of 0.762 (10):0.238 (10).
PMCID: PMC3297233  PMID: 22412423
7.  25,26,27,28-Tetra­propoxycalix[4]arene-5,17-dicarbonitrile 
In the title compound, C42H46N2O4, both crystallographically independent mol­ecules display a 1,3-alternate conformation. Their crystal packing is stabilized by non-classical C—H⋯N hydrogen bonds. The dihedral angles between the planes of the aromatic rings and the mean plane through the methyl­ene C atoms bridging the aromatic rings are 78.10 (13), 80.74 (14), 81.89 (12) and 79.05 (14)° for the first mol­ecule, and 71.65 (11), 76.60 (13), 77.97 (14) and 74.76 (13)° for the second mol­ecule. Both mol­ecules have three C atoms of one prop­oxy chain disordered over two set of sites; the site-occupancy factors are 0.7/0.3 and 0.6/0.4, respectively.
PMCID: PMC2979721  PMID: 21579836
8.  5-Ethyl-4a-meth­oxy-1,3-dimethyl-4a,5-dihydro­benzo[g]pteridine-2,4(1H,3H)dione 
The title compound, C15H18N4O3, was formed by the reaction of methanol with 5-ethyl-1,3-dimethyl­alloxazinium perchlorate. Its structure mimics those of possible flavin inter­mediates in flavoenzymes. The heterocyclic rings are substituted with methyl, ethyl and meth­oxy groups. The central tricyclic skeleton is bent due to the presence of an sp 3 C atom. There are weak inter­molecular C—H⋯O inter­actions in the structure, forming a three-dimensional network.
PMCID: PMC2969355  PMID: 21582825

Results 1-8 (8)