Physical and structural studies of N-carboxymethyl- and N-(p-methoxyphenyl)-3-hydroxy-2-methyl-4-pyridinone

1992 ◽  
Vol 70 (3) ◽  
pp. 763-770 ◽  
Author(s):  
Zaihui Zhang ◽  
Steven J. Rettig ◽  
Chris Orvig
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Protonation Constant ◽  
Direct Methods ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

3-Hydroxy-1-carboxymethyl-2-methyl-4-pyridinone (Hcmp) and 3-hydroxy-1-(p-methoxyphenyl)-2-methyl-4-pyridine (Hpap) have been prepared and studied by single crystal X-ray diffraction. Crystals of Hemp are monoclinic, a = 6.340 (2), b = 7.705 (1), c = 16.226 (1) Å, β = 94.74 (1), Z = 4, space group P21/n and those for Hap are monoclinic, a = 10.8435 (9), b = 16.680 (2), c = 13.5665 (6) Å, β = 109.450 (4), Z = 8, space group C2/c. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.030 and 0.041 (Rw = 0.039 and 0.058) for 1642 and 1819 reflections with I ≥ 3σ(I), respectively. Bond lengths and bond angles in the two compounds are normal; however, Hcmp forms as a zwitterion in the solid state. The two compounds were also studied by mass spectrometry, UV, infrared, proton NMR spectroscopies, and potentiometric equilibrium measurements. The protonation constants for Hcmp are log K1 = 9.76 (1), log K2 = 3.43 (1), and log K3 = 2.78 (3) and for Hpap are [Formula: see text] and [Formula: see text]. Keywords: 3-hydroxy-4-pyridinone, zwitterion, hydrogen bonding, protonation constant, crystallography, solid state.

Physical and structural studies of N-substituted-3-hydroxy-2-methyl-4(1H)-pyridinones

1988 ◽  
Vol 66 (1) ◽  
pp. 123-131 ◽  
Author(s):  
William O. Nelson ◽  
Timothy B. Karpishin ◽  
Steven J. Rettig ◽  
Chris Orvig
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Single Crystal ◽  
Direct Methods ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

A series of 3-hydroxy-2-methyl-4(1H)-pyridinones has been prepared with the substituents H, CH3, n-C6H11, and CH2CH2NH2 at the ring N. The dipyridinone 1,6-bis(3-hydroxy-2-methyl-4(1H)-pyridinon-1-yl)hexane has also been synthesized. The products with H and CH3 substituents have been studied by single crystal X-ray diffraction. Crystals of 3-hydroxy-2-methyl-4-pyridinone are monoclinic, a = 6.8351(4), b = 10.2249(4), c = 8.6525(4) Å, β = 105.215(4)°, Z = 4, space group P21/n and those of 3-hydroxy-1,2-dimethyl-4-pyridinone are orthorhombic, a = 7.3036(4), b = 13.0490(6), c = 13.7681(7) Å, Z = 8, space group Pbca. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.037 and 0.044 for 914 and 857 reflections with I ≥ 3σ(I), respectively. Bond lengths and angles in the two compounds were normal. All the compounds have been studied by mass spectrometry, and by infrared and proton nmr spectroscopies. The importance of hydrogen bonding to both the solution and solid state properties of these compounds has been confirmed by these techniques.

Structural studies of organoboron compounds. LVI. 1-Benzyl-7-methyl-3,5-diphenyl-2,4,6-trioxa-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane and 1,4,6,9-tetramethyl-2,7-diphenyl-3,8,11,12-tetraoxa-1,6-diazonia-2,7-diboratatricyclo[5.3.1.12,6]dodecane

1992 ◽  
Vol 70 (11) ◽  
pp. 2809-2817 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Structural Studies ◽  
Triclinic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Molar Ratios ◽  
New Type

The preparation of the N-(2-hydroxypropyl)-N-alkylhydroxylamines, 6a (R = CH3) and 6b (R = CH2Ph), and their reactions with phenylboronic acid are described. Regardless of the molar ratios of reactants employed, the reaction with 6b leads to the 1:2 condensate 1-benzyl-7-methyl-3,5-diphenyl-2,4,6-trioxa-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane, 7, while that with 6a gives rise to the 1:1 condensate 1,4,6,9-tetramethyl-2,7-diphenyl-3,8,11,12-tetraoxa-1,6-diazonia-2,7-diboratatricyclo[5.3.1. 12,6]dodecane, 11 (the cyclic BONBON dimer of 4,6-dimethyl-2-phenyl-1,3-dioxa-4-aza-2-boracyclohexane, 9). Compounds 7 and 11 both crystallize in the triclinic space group [Formula: see text]: for 7; a = 13.126(1), b = 15.337(1), c = 10.9469(5) Å, α = 91.727(5), β = 104.647(5), γ = 72.922(7)°, Z = 4; and for 11; a = 9.0807(4), b = 9.1653(3), c = 6.4876(2) Å, α = 97.708(3), β = 108.830(3), γ = 89.188(4)°, Z = 1. The structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.038 and 0.032 for 5879 and 1827 reflections with I ≥ 3σ(F2), respectively. Compound 7 has the expected bicyclic pyroboronate structure, but represents the first reported N-substituted example of this type of compound. Bond lengths involving boron in 7 are (C) O—B(sp3) = 1.428(2) and 1.420(2), (B)O—B(sp3) = 1.472(2) and 1.468(2), N—B(sp3) = 1.737(2) and 1.762(2), C(phenyl)—B(sp3) = 1.588(2) and 1.584(2), (N)O—B(sp2) = 1.402(2) and 1.404(2), (B)O—B(sp2) = 1.331(2) and 1.329(2), C(phenyl)—B(sp2) = 1.555(3) and 1.553(2) Å. The X-ray analysis establishes a centrosymmetric, twofold N → B coordinated, dimeric structure in the solid state for 11 in which each B—O—N segment of a central six-membered BONBON ring is bridged by an O—C—C moiety. Compound 11 represents the first fully characterized example of a new type of "BONBON" compound. Bond distances involving the boron atom are (N)O—B = 1.465(1), (C)O—B = 1.428(1), N—B = 1.695(2), and C(phenyl)—B = 1.607(2) Å. Spectroscopic evidence indicates that in solution and in the gas phase this material exists predominantly as the monomer 9.

Structural studies of organoboron compounds. XXXII. 5,5-Difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene and 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene

1988 ◽  
Vol 66 (10) ◽  
pp. 2621-2630 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Least Squares ◽  
Crystal Structures ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Conformational Isomers

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 5,5-difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are triclinic, a = 6.1576(3), b = 11.2651(3), c = 10.8118(3) Å, α = 109.747(3), β = 105.807(4), γ = 92.976(4)°, Z = 2, space group [Formula: see text], and those of 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are monoclinic, a = 9.8549(6), b = 10.9242(6), c = 41.263(2) Å, β = 92.717(6)°, Z = 8, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.045 and 0.042 for 2344 and 4248 reflections with I ≥ 3σ(I), respectively. The molecules were both found to possess a seven-membered chelate structure, the O,O-chelatїng ligand being strongly bound to the X2B moiety. Two conformational isomers of the X = Ph compound were found in the solid state. The 2-oxazoline N-oxide moieties present in both compounds are the first to be structurally characterized. Important mean libration-corrected bond lengths are: O—B = 1.491 and F—B = 1.387 Å for X = F; O—B = 1.511 and C—B = 1.620 Å for X = Ph.

Structural studies of organoboron compounds. LX. Reaction of sterically hindered arylboronic acids with 2-(hydroxyamino)alkanols. Crystal and molecular structure of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane

1994 ◽  
Vol 72 (4) ◽  
pp. 1154-1161 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Arylboronic Acids ◽  
Sterically Hindered

Three 2-(hydroxyamino)alkanols have been reacted with sterically hindered arylboronic acids, ArB(OH)2. When Ar = o-tolyl, 1:2 condensates having bicyclic structures are formed but when Ar = mesityl (2,4,6-(CH3)3C6H2), 1:1 condensates having six-membered cycloboronate structures result. These 1:1 condensates represent the first examples of N-unsubstituted 1,3-dioxa-4-aza-2-boracyclohexane derivatives. An X-ray analysis of one example provides unambiguous proof of the structure. Crystals of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane, 3c, are monoclinic, a = 11.076(9), b = 23.94(2), c = 13.414(9) Å, β = 109.40(5)°, Z = 8, space group P21/n. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R = 0.051 and Rw = 0.058 for 2037 reflections with I ≥ 3σ(F2).

Ring contraction of 4-substituted 2,6-dichlorophenols. The crystal structure of 2,2,4α,5α-Tetrachloro-1α,3α-dihydroxycyclopentane-1,4-carbolactone

1977 ◽  
Vol 30 (10) ◽  
pp. 2195 ◽  
Author(s):  
RM Christie ◽  
RW Rickards ◽  
KJ Schmalzl ◽  
D Taylor
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Major Product ◽  
X Ray Diffraction ◽  
Ring Contraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Counter Data

Alkaline chlorination of the 4-alkyl-2,6-dichlorophenols (2b) and (2c) proceeds through ring contraction and halolactonization to form the 4α- alkyl-2,2,5α-trichloro-1α,3α-dihydroxycyclopentane-1,4-carbolactones (4b) and (4c). Under similar conditions, 2,4,6-trichlorophenol affords the analogous 2,2,4α,5α-tetrachloro-1α,3α-dihydroxycyclopentane-1,4- carbolactone (4a) in low yield, in addition to the Hantzsch acid (3a) as the major product. The acid (3a) upon further treatment undergoes chloro-lactonization to give the lactone (4a). The structures of the lactones (4b) and (4c) follow from spectroscopic comparison with (4a), the structure of which has been established by X-ray diffraction (C6H4Cl4O4 orthorhombic a 13.485(1), b 12.348(1), c 11.371(1) Ǻ, space group Pccn, Z 8, solved by direct methods and refined by block-diagonal and full-matrix least squares to R 0.031, Rw 0.043 for 1313 unique counter data with I/σ(I) ≥ 3.0).

Structural studies of organoboron compounds. XIX. 1,7-Dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane

1984 ◽  
Vol 62 (3) ◽  
pp. 515-520 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Least Squares ◽  
Variable Temperature ◽  
Direct Methods ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
H Nmr ◽  
Valence Tautomers

Crystals of 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane are triclinic, a = 10.559(2), b = 15.156(3), c = 10.338(2) Å, α = 99.14(1), β = 89.90(1), γ = 96.73(1)°, Z = 4, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.032 and Rw = 0.038 for 2396 reflections with I ≥ 3σ(I). The structure consists of two crystallographically independent, but virtually identical, molecules containing sterically lengthened N—B coordinative bonds (mean 1.740(3) Å). The structurally inequivalent (in the solid state) pairs of N-methyl and B-phenyl groups are observed by variable temperature 1H nmr to be magnetically equivalent in solution, implying a rapid interconversion of "valence tautomers" at temperatures down to −60 °C.

Structural studies of organoboron compounds. LVII. Synthesis and structure of bicyclic boron-nitrogen betaines. 1-Methyl-5-(3-nitrophenyl)-4,6,9-trioxa-1-azonia-5-boratabicyclo[3.3.1]nonane and 3,3,4-trimethyl-1-(3-nitrophenyl)-2,6,7-trioxa-3-azonia-1-boratabicyclo[2.2.2]octane

1993 ◽  
Vol 71 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Eckart Ahlenstiel ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Least Squares ◽  
Boron Atom ◽  
Crystal Packing ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Boron Nitrogen ◽  
Tetrahedral Boron

The syntheses and structures of the bicyclic boron-nitrogen betaines 1-methyl-5-(3-nitrophenyl)-4,6,9-trioxa-1-azonia-5-boratabicyclo[3.3.1]nonane, 7a, and 3,3,4-trimethyl-1-(3-nitrophenyl)-2,6,7-trioxa-3-azonia-1-boratabicyclo[2.2.2]-octane, 14a, are reported. Crystals of 7a are orthorhombic, a = 20.256(2), b = 37.652(2), c = 6.642(1) Å, Z = 16, space group Fdd2, and those of 14a are orthorhombic, a = 21.402(2), b = 11.334(3), c = 11.248(2) Å, Z = 8, space group Pbca. The structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.038 and 0.045 (Rw = 0.036 and 0.053) for 975 and 1646 reflections with I ≥ 3σ(F2), respectively. The X-ray analyses establish the bicyclo[3.3.1]nonane and bicyclo[2.2.2]octane "cage" structures for 7a and 14a, respectively. Bond lengths involving the tetrahedral boron atom are (N)O—B = 1.519(5), (C)O—B = 1.444(6) and 1.443(6), C(aryl)—B = 1.602(5) Å for 7a; and (N)O—B = 1.530(3), (C)O—B = 1.446(3) and 1.455(3), C(aryl)—B = 1.608(3) Å for 14a. Weak [Formula: see text] interactions are the main feature of the crystal packing arrangements of both compounds.

Complexes of 15-crown-5 and cyclohexano-15-crown-5 with lithium, sodium, and potassium phenoxide having macrocycle: salt ratios of 1:1 and 1:2. The crystal structures of two polymorphs of 15-crown-5•2LiOPh

1988 ◽  
Vol 66 (10) ◽  
pp. 2515-2523 ◽  
Author(s):  
Michael P. Murchie ◽  
John W. Bovenkamp ◽  
André Rodrigue ◽  
Kimberley A. Watson ◽  
Suzanne Fortier
Keyword(s):  
Crystal Structures ◽  
Direct Methods ◽  
The Other ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Diffraction Structure ◽  
Structure Determinations ◽  
Sodium And Potassium

The syntheses, in ethereal solvents, of the complexes of 15-crown-5 and cyclohexano-15-crown-5 with lithium, sodium, and potassium phenoxide are described. The two macrocycles form complexes with lithium and sodium phenoxide with host:guest ratios of 1:2. Potassium phenoxide, however, was complexed by the two macrocycles to give products with macrocycle:salt ratios of 1:1. Crystals of 15-crown-5•2LiOPh were obtained for X-ray diffraction structure determinations. In fact, the crystal structures of two co-crystallizing polymorphs of this complex (1a and 1b) have been determined. Polymorph 1a crystallizes in space group [Formula: see text] with a = 11.386(4), b = 11.901(4), c = 10.654(4) Å, α = 106.53(3), β = 112.60(3), γ = 106.52(3)°, and Z = 2. Polymorph 1b crystallizes in space group P21/n with a = 15.355(4), b = 11.642(2), c = 13.595(6) Å, β = 104.56(3)°, and Z = 4. Both structures were solved by direct methods, and refined by full-matrix least-squares calculations to residuals, R, of 0.053 and 0.055 for polymorphs 1a and 1b, respectively. The structures of the two polymorphs differ only in the orientation of the phenoxides. The structures show a dimer, (15-crown-5•2LiOPh)2, which consists of an aggregate of four lithium phenoxide molecules complexed by two 15-crown-5 macrocycles. The two lithiums of each monomeric unit of this dimer have different crystallographic and chemical environments. One lithium is coordinated to all five oxygens of the macrocycle and to one of the phenoxide oxygens while the other lithium is coordinated to only one oxygen of the macrocycle and to three phenoxide oxygens.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

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