Rearrangement products of 3-methanesulfonyl-N-methyl-N-nitroaniline.

Two isomeric products (C 8 H 10 N 2 O 4 S) of the rearrangement of 3-methanesulfonyl-N-methyl-N-nitroaniline have been investigated, viz. 3-methanesulfonyl-N-methyl-2-nitroaniline, which was the main product of the rearrangement, and 5-methanesulfonyl-N-methyl-2-nitroaniline. In both molecules, the aromatic rings are appreciably deformed towards ortho-quinonoidal geometry by electronic and steric interactions. The crystal structure is stabilized, in both cases, by weak C-H...O hydrogen bonds.

4,4,4′,4′,7,7′-Hexamethyl-2,2′-spirobichroman

The title compound, C23H28O2, was obtained from the reaction of acetone with meta-cresol. The molecular structure consists of two identical subunits which are nearly perpendicular to each other. The oxygen-containing rings are not planar and the molecule is chiral. The crystal structure consists of chains of molecules of the same chirality arranged along the [010] axis.

N-(3H-Thia­zol-2-yl­idene)­nitr­amine and N-methyl-N-(thia­zol-2-yl)­nitr­amine

The geometries of the thiazole ring and the nitramino groups in N-(3H-thiazol-2-ylidene)nitramine, C 3 H 3 N 3 O 2 S, (I), and N-methyl-N-(thiazol-2-yl)nitramine, C 4 H 5 N 3 O 2 S, (II), are very similar. The nitramine group in (II) is planar and twisted along the C-N bond with respect to the thiazole ring. In both structures, the asymmetric unit includes two practically equal molecules. In (I), the molecules are arranged in layers connected to each other by N-H...N and much weaker C-H...O hydrogen bonds. In the crystal structure of (II), the molecules are arranged in layers bound to each other by both weak C-H...O hydrogen bonds and S...O dipolar interactions.

1,4-Dihydro-1-methyl-4-nitriminopyridine Dihydrate

Molecules of the title compound, C6H7N302.2H20, are almost planar with the NNO2 nitrimino group twisted 8 (1) ° out of the plane of the pyridine ring. The nitrimino group and CsN ring form a conju- gated 7r-electron system. These molecules together with water molecules are arranged in planes, They are con- nected with each other by O--H.-.O, O--H...N and weaker C--H..-O hydrogen bonds. Four water mol- ecules form a planar square (OH..-O--H)2 ring with O-..O distances equal to 2.741 (2) and 2.778(2)A. These rings join pairs of molecular planes into double layers, interacting otherwise by van der Waals forces.

ChemInform Abstract: 4,4,4′,4′,7,7′-Hexamethyl-2,2′-spirobichroman.

The title compound, C23H28O2, was obtained from the reaction of acetone with meta-cresol. The molecular structure consists of two identical subunits which are nearly perpendicular to each other. The oxygen-containing rings are not planar and the molecule is chiral. The crystal structure consists of chains of molecules of the same chirality arranged along the [010] axis.

By-products in the rearrangement of N-methyl-N-phenylnitramine

Abstract N-Methyl-N-phenylnitramine was rearranged in the aqueous dioxane — sulphuric acid mixture to 2-nitro- and 4-nitro-N-methylanilines. The isomer ratio was independent of the acidity within the range of −0.3 > Ho > −2.8. Some by-products were isolated and identified e.g. N-methyl-N-nitrosoaniline, its 2-nitro and 4-nitro derivatives, nitrosobenzene and 4′,4″-bis-(N-methylamino)-3′,3″-dinitrodiphenylmethane. The mechanism of the nitramine rearrangement is discussed.

Rearrangement of N-(3-pyridyl)nitramine

AbstractContrary to other N-(pyridyl)nitramines, the title compound cannot be rearranged to 3-amino-2-nitropyridine or other isomers. Hypothetical products of its transformation under influence of concentrated sulphuric acid, viz. 3-hydroxypyridine, 3,3′-azoxypyridine and 3,3′-azopyridine, were obtained from 3-nitro- and 3-aminopyridine in oxidation and reduction reactions. N-(3-Pyridyl)nitramine was prepared and rearranged in concentrated sulphuric acid. 3-Hydroxypyridine and 3,3′-azoxypyridine were isolated from the reaction mixture, other products were identified by the HPLC and GCMS methods. The results indicate that N-(3-pyridyl)hydroxylamine is an intermediate formed from N-(3-pyridyl…

Structure of N,4-dinitroaniline and its complex with sulfolane at 85 K; on the proton donor–acceptor affinity of the primary nitramine (HNNO2) group

The NNO2 group of the title compound is significantly less twisted with respect to the aromatic ring in comparison to a typical secondary nitramine. The amide nitrogen is trigonally hybridized. The nitramino group is almost planar. The C—C—N—N torsion angles vary between ca 13 and 42°, whereas the twist along the N—N bond is much smaller and amounts to between ca 1 and 15°. Those twist angles are governed by a crystal packing and are much larger in the case of crystals of pure N,4-dinitroaniline in comparison to that of its complex with sulfolane. The deviations of the internal angles of the aromatic ring from 120° do not exceed 3°. The presence of the nitro group increases the C—C—C valenc…

Structure and properties of N-methyl-N-(4-pyridyl)-nitramine and 1,4-dihydro-1-methyl-4-nitriminopyridine

Abstract The molecular structure and spectral properties of N -methyl- N -(4-pyridyl)-nitramine ( 1 ) and 1,4-dihydro-1-methyl-4-nitriminopyridine ( 3 ) were investigated by the X-ray diffraction, FTIR, nuclear magnetic resonance (NMR) methods and DFT theoretical calculations. N -methyl- N -(4-pyridyl)-nitramine ( 1 ) crystallises in the orthorhombic Pbca space group. It is composed of two planar fragments; nitramino (N 2 O 2 ) group and the pirydyl ring. These two groups are twisted at about 70° with respect to each other, along the Ar–N bond. On the contrary, in compound 3 , they are coplanar to each other. Twist of the nitramino group in 1 with respect to the pirydyl ring leads to a sign…

ChemInform Abstract: Attempted Preparation of Trisphenol-II.

Abstract Condensation of 4,4-bis-(4-methoxyphenyl)-2-methyl-2-pentanol with phenol, in the presence of hydrogen chloride, gives 1,3,3-trimethyl-1-(4-methoxyphenyl)-5-methoxyindan and tris-(4-methoxyphenyl)-ethane instead of expected 2,2,4-tris-(4-methoxyphenyl)-4-methylpentane (trisphenol-II). tris-(4-Hydroxyphenyl)-ethane was obtained, together with bisphenol-A, by condensation of phenol with acetylacetone.

1-Nitroindoline.

In the title compound, C(8)H(8)N(2)O(2), the nitramino group is planar and only slightly twisted with respect to the indoline rings. The bridgehead N--C bond is slightly shorter than in typical secondary aromatic nitramines. The N--N bond has some double-bond character. The molecules are connected by weak C--H...O hydrogen bonds, forming chains parallel to the z direction.

Disorder in the crystals of trans-4-fluoroazoxybenzene. Synthesis, spectral properties, crystal structures and DFT calculations

Abstract Two crystals of trans-4-fluoroazoxybenzene were obtained using two different methods. Oxidation of 4-fluoroazobenzene provided crystals of trans-4-fluoroazoxybenzene (I) consisting of two isomers; 51% α (ONN) and 49% β (NNO) isomer. From trans-amino-azoxybenzenes in Schiemann reaction it were obtained crystals of trans-4-fluoro-NNO-azoxybenzenes (II, β isomer) containing 4.7% of the α-isomer according to the HPLC analysis. The crystal structures of I and II were determined by the X-ray diffraction method. In the crystal I two nitrogen atoms of azoxy bridge and fluorine atom are disordered. In the crystal II, there are two independent molecules of trans-4-fluoroazoxybenzene; the mol…

Structure and properties of some nitro derivatives of N -methyl- N -phenylnitramine

Abstract Ten mono-, di- and tri-nitro derivatives of N-methyl-N-phenylnitramine were prepared and investigated using spectral and electrooptical methods. Three of them, viz. N-(2, 5-dinitrophenyl)-N-methylnitramine (monoclinic, P21/c, a=8.248(2), b=11.655(2), c=10.404(2) A , β=102.57(2)°), N-(2,3-dinitrophenyl)-N-methylnitramine (monoclinic, P21/c, a=9.224(2), b=7.222(2), c=15.458(4) A , β=101.08(2)°)) and N-(3,5-dinitrophenyl)-N-methylnitramine (monoclinic, P21/n, a=9.814(2), b=12.000(2), c=8.865(2) A , β=114.94(2)°) were examined by the X-ray diffraction method. The nitramino group is nearly planar with the short N(7)–N(8) bond and strongly electron deficient N(8) atom. The nitramino grou…

Twotrans-4-aminoazoxybenzenes

Two isomeric trans-4-aminoazoxybenzenes, trans-1-(4-aminophenyl)-2-phenyldiazene 2-oxide (alpha, C(12)H(11)N(3)O) and trans-2-(4-aminophenyl)-1-phenyldiazene 2-oxide (beta, C(12)H(11)N(3)O), have been characterized by X-ray diffraction. The alpha isomer is almost planar, having torsion angles along the C(aryl)-N bonds of only 4.9 (2) and 8.0 (2) degrees. The relatively short C(aryl)-N bond to the non-oxidized site of the azoxy group [1.401 (2) A], together with the significant quinoid deformation of the respective phenyl ring, is evidence of conjugation between the aromatic sextet and the pi-electron system of the azoxy group. The geometry of the beta isomer is different. The non-substitute…

SYNTHESIS AND REARRANGEMENT OFN-METHYL-N-(2-THIAZOLYL)-NITRAMINE

Methylation of N-(2-thiazolyl)-nitramine in alkaline solution gives 1,2-dihydro-3-methyl-2-nitriminothiazole which rear-ranges in concentrated sulphuric acid yielding small amount of 2-(N-methylamino)-5-nitrothiazole, identical with the product of rearrangement of N-methyl-N-(2-thiazolyl)-nitramine. The latter compound was obtained by the action of sodium hydride on 2-(N-methylamino)-thiazole followed by the nitration with n-butyl nitrate.

1,5-Dimethyl-2-nitrimino-1,2-dihydropyridine

Methyl­ation of 5-methyl-2-nitramino­pyridine provides the title compound, C7H9N3O2, as the only product. The mol­ecule consists of two planar fragments, viz. an aromatic ring and a nitrimino substituent. The NNO2 group is twisted by 17 (2)° out of the plane of the pyridine ring. Despite a small torsion angle between these fragments, the geometry of the mol­ecule indicates the participation of the π-electrons in the C—N bond. The hydrogen bonds in the crystal structure seem to be too weak to generate any deformations observed in the mol­ecule.

9-Methyl-3-phenyldiazenyl-9H-carbazole: X-ray and DFT-calculated structures

The title compound, C19H15N3, was prepared by condensation of 3-nitroso­carbazole and aniline with subsequent methyl­ation. The structure is built up of stacks of almost planar mol­ecules. Density functional theory (DFT) calculations predict a completely planar conformation, different from that observed in the crystal lattice. HOMA (harmonic oscillator model of aromaticity) indices, calculated for three aromatic rings, demonstrate the small influence of the azo substituent on π electrons in the carbazole system.

2,3-Dihydro-3-methyl-2-nitrimino-1,3-thiazole

The title compound ¿alternatively, 3-methyl-2-[oxido(oxo)hydrazono]-2,3-dihydro-1,3-thiazole¿, C(4)H(5)N(3)O(2)S, was obtained by methylation of N-(2-thiazolyl)nitramine. The molecule lies on a mirror plane and the thiazole ring is planar, regular in shape and aromatic. The S atom participates in the aromatic sextet via an electron pair on the 3p(z) orbital. In the crystal, the molecules are arranged in parallel layers, bound to each other by weak C-H.O and C-H.N hydrogen bonds and by S.O dipolar interactions, with an interlayer separation of 3.23 A.

Synthesis of 2-Aminothiazole Derivatives in Easy Two-Step, One-Pot Reaction

4-Chloro-N-methyl-N-nitroaniline

The molecular structure of (p-ClC 6 H 4 )(CH 3 )NNO 2 (or C 7 H 7 ClN 2 O 2 ) contains a planar NNO 2 nitroamino group which is twisted about the N-C phenyl bond by ca 68° from the plane of the aromatic ring. The structural data are in agreement with the spectral results and indicate that there is no conjugation between the aromatic sextet and the nitroamino group. There are no specific intermolecular interactions.

2,4,6-Trimethyl-N-nitroaniline

In 2,4,6-trimethyl-N-nitro­aniline (alternatively called mesitylnitramine), C9H12N2O2, the primary nitramino group is planar with a short N—N bond and is nearly perpendicular to the aromatic ring. The methyl group located in the para position is disordered, each H atom having half-occupancy. The mol­ecules are linked together along the [100] axis by inter­molecular N—H⋯O hydrogen bonds.

4-hydroxy-ONN-azoxybenzene

The oxidation of 4-hydroxy­azo­benzene provided a mixture of two azoxy compounds, which were separated by column chromatography. The isomer with the higher melting point appeared to belong to the α (ONN) series, as determined by X-ray diffraction. The mol­ecule, C12H10N2O2, is almost planar. The benzene rings are twisted by 11.7 (2) (substituted) and 4.1 (1)° (unsubstituted) with respect to the ONN plane. The mol­ecules are connected to one another by strong O—H⋯O hydrogen bonds forming chains extended along [001], which are bound by much weaker C—H⋯O hydrogen bonds forming layers in the bc plane.

1-Methyl-4-nitraminopyridinium nitrate and 4-nitraminopyridinium methanesulfonate

In the title compounds, C6H8N3O2+*NO3- and C5H6N3O2+*-CH3SO3-, respectively, the cations are almost planar; the twist of the nitramino group about the C-N and N-N bonds does not exceed 10 degrees. The deviations from coplanarity are accounted for by intermolecular N-H...O interactions. The coplanarity of the NHNO2 group and the phenyl ring leads to the deformation of the nitramino group. The C-N-N angle and one C-C-N angle at the junction of the phenyl ring and the nitramino group are increased from 120 degrees by ca 6 degrees, whereas the other junction C-C-N angle is decreased by ca 5 degrees. Within the nitro group, the O-N-O angle is increased by ca 5 degrees and one O-N-N angle is decr…

β-(3,6,9-Trimethyl-9-xanthenyl)propionic acid

The title compound, C19H20O3, was obtained, among other condensation products, from the reaction of meta-cresol and levulinic acid. The pyrane ring closure does not alter significantly the environment of the ethereal linkage in comparison with diaryl ethers. The deformations of the endocyclic valence angles in the benzene rings, centred on the C atoms substituted with alkyl groups, is greater than expected. The mol­ecular packing is influenced by O—H⋯O hydrogen bonds, leading to centrosymmetric dimers.

Charge-density analysis of 1-nitroindoline: refinement quality using free R factors and restraints

Nitramines and related N-nitro compounds have attracted significant attention owing to their use in rocket fuel and as explosives. The charge density of 1-nitroindoline was determined experimentally and from theoretical calculations. Electron-density refinements were performed using the multipolar atom formalism. In order to design the ideal restraint strategy for the charge-density parameters, R-free analyses were performed involving a series of comprehensive refinements. Different weights were applied to the charge-density restraints, namely the similarity between chemically equivalent atoms and local symmetry. Additionally, isotropic thermal motion and an anisotropic model calculated by …

Attempted preparation of trisphenol-II

Abstract Condensation of 4,4-bis-(4-methoxyphenyl)-2-methyl-2-pentanol with phenol, in the presence of hydrogen chloride, gives 1,3,3-trimethyl-1-(4-methoxyphenyl)-5-methoxyindan and tris-(4-methoxyphenyl)-ethane instead of expected 2,2,4-tris-(4-methoxyphenyl)-4-methylpentane (trisphenol-II). tris-(4-Hydroxyphenyl)-ethane was obtained, together with bisphenol-A, by condensation of phenol with acetylacetone.

Crystal and molecular structure of 1,2-dihydro-1-methyl-2-nitriminopyridine: X-ray and infrared studies

Abstract The crystal and molecular structure of 1,2 dihydro-1-methyl-2-nitriminopyridine ( 1 ) at 90.0(1) K have been determined. It crystallises in an orthorhombic Pna2 1 space group with a =7.753(2), b =13.829(3) and c =6.070(1) A, Z =4, R ( F )=0.0259 for 1856 unique reflections. The pyridine ring is planar, the N(1) nitrogen atom remains sp 2 hybridised. The NNO 2 group is twisted 26° along C–N bond and 15° along N–N bond. The twist is caused by a steric hindrance and/or weak C–H⋯O hydrogen bonds. IR spectra of ( 1 ), N -(2-pyridyl)-nitramine ( 4 ) and N -methyl- N -(2-pyridyl)-nitramine ( 9 ) were recorded in solution and in the solid state. The frequencies characteristic of the nitrim…

Charge-density analysis of 1-nitroindoline: refinement quality using free R factors and restraints. Corrigendum

The D e (dissociation energy) values in Table 6 of the article by Zarychta et al. [(2011). Acta Cryst. B67, 250–262] are corrected.

Acidity and basicity of primaryN-phenylnitramines: catalytic effect of protons on the nitramine rearrangement

Para-substituted N-phenylnitramines were prepared either by oxidation of diazonium salts or by nitration under alkaline or acidic conditions. Isotopic [15N-NO2] labelling indicated that the bands characteristic of the N-nitro group appear in the 1318–1323 and 1585–1607 cm−1 regions. In the nitrogen NMR spectra, the nitramino group gives two resonances at −193 ± 3 (NH) and −32 ± 3 ppm (NO2). The chemical shifts in proton and carbon NMR spectra are predictable, based on increments and the additivity rule. The spectral data indicate the lack of conjugation between the nitramino group and another substituent bound to the ring. It seems to contradict the well-known fact that substituents strongl…

9,9′-Bianthracenyl

The title compound, C28H18, has two nearly planar anthracenyl fragments which are twisted with respect to one another by 80.54 (2)° around the central C—C bond which is very long [1.4954 (17) Å]. The structure differs from the already known polymorph [Langer, Sieler & Becker (1992). Z. Kristallogr. 199, 300–303].

trans-4-Bromo-ONN-azoxybenzene at 100 K.

The crystal structure of the alpha isomer of trans-4-bromoazoxybenzene [systematic name: trans-1-(bromophenyl)-2-phenyldiazene 2-oxide], C(12)H(9)BrN(2)O, has been determined by X-ray diffraction. The geometries of the two molecules in the asymmetric unit are slightly different and are within approximately 0.02 A for bond lengths, approximately 2 degrees for angles and approximately 3 degrees for torsion angles. The azoxy bridges in both molecules have the typical geometry observed for trans-azoxybenzenes. The crystal network contains two types of planar molecules arranged in columns. The torsion angles along the Ar-N bonds are only 7 (2) degrees, on either side of the azoxy group.

Orthorhombic polymorphs of twotrans-4-aminoazoxybenzenes

The two isomeric compounds 4-amino-ONN-azoxybenzene [or 1-(4-aminophenyl)-2-phenyldiazene 2-oxide], i.e. the alpha isomer, and 4-amino-NNO-azoxybenzene [or 2-(4-aminophenyl)-1-phenyldiazene 2-oxide], i.e. the beta isomer, both C(12)H(11)N(3)O, crystallized from a polar solvent in orthorhombic space groups, and their crystal and molecular structures have been determined using X-ray diffraction. There are no significant differences in the bond lengths and valence angles in the two isomers, in comparison with their monoclinic polymorphs. However, the conformations of the molecules are different due to rotation along the Ar-N bonds. In the alpha isomer, the benzene rings are twisted by 31.5 (2)…

CCDC 623096: Experimental Crystal Structure Determination

Related Article: Błażej Dziuk, Janusz B. Kyzioł, Jacek Zaleski, Krzysztof Ejsmont, Bartosz Zarychta|2018|J.Heterocycl.Chem.|55|763|doi:10.1002/jhet.3086

CCDC 623097: Experimental Crystal Structure Determination

Related Article: Błażej Dziuk, Janusz B. Kyzioł, Jacek Zaleski, Krzysztof Ejsmont, Bartosz Zarychta|2018|J.Heterocycl.Chem.|55|763|doi:10.1002/jhet.3086