Bemerkungen zur Synthese von 5-Amino-m-xylol-2-sulfonsäure und 5-Amino-m-xylol-4-sulfonsäure

Some comments on the syntheses of 5-amino-m-xylene-2-sulfonic acid and 5-amino-m-xylene-4-sulfonic acid Treatment of 5-amino-m-xylene ( 1 ) with oleum led to a 55:45 mixture of 5-amino-m-xylene-2-sulfonic acid ( 2 ) and 5-amino-m-xylene-4-sulfonic acid ( 3 ). The structure of both isomers was proven by reaction of sulfur dioxide with the diazonium chlorides derived from 2-amino-5-nitro-m-xylene ( 5 ) and 4-amino-5-nitro-m-xylene ( 8 ) giving 5-nitro-m-xylene-2-sulfonyl chloride ( 6 ) and 5-nitro-m-xylene-4-sulfonyl chloride ( 9 ) respectively, followed by hydrolyses to the corresponding sulfonic acids 7 and 10 , and final Béchamp reductions. The sulfonic acid 2 was also prepared by sulfonation of 5-acetylamino-m-xylene ( 4 ) to 5-acetylamino-m-xylene-2-sulfonic acid ( 11 ) and subsequent hydrolysis. A further procedure for the synthesis of 3 was sulfonation of 5-amino-2-chloro-m-xylene ( 12 ) – prepared by Béchamp reduction of 2-chloro-5-nitro-m-xylene ( 13 ) – or of 5-amino-2-bromo-m-xylene ( 15 ) – prepared by bromination of 4 and subsequent hydrolysis – to 5-amino-2-chloro-m-xylene-4-sulfonic acid ( 16 ) and 5-amino-2-bromo-m-xylene-4-sulfonic acid ( 17 ) respectively, followed by hydrogenolysis.     

Über die Strukturaufklärung von (Hydroxy-oxo-cyclopentenyl)alkansäuren,den Aldolkondensationsprodukten von Dioxoencarbonsäuren aus Rinderleber

Structure Elucidation of (Hydroxy-oxo-cyclopentenyl)alkanoic Acids, the Aldol-Condensation Products of Dioxoene Acids from Cattle Liver During homogenization of cattle liver the highly instable dioxoene acids 13a , 13b , and 13c are formed. These acids cyclize in alkaline solution to yield pairs of stable (hydroxy-oxo-cyclopentenyl)alkanoic acids, which were isolated as methyl esters 4a / 5a , 4b / 5b , and 4c / 5c . The structures of these compounds were deduced from an enriched 3-mg mixture sample by microchemical reactions combined with a GC/MS analysis of the reaction products. Compound 13a was obtained as methyl ester by oxidation of the methyl ester of the corresponding F-acid with NaOCl. It was not possible to isolate 13a in pure form due to its high sensitivity. Instead of the methyl ester of 13a , 4a and 5a were isolated, of which the structures were established.     

Synthesis and Molecular Structure of New S‐Nucleosides of 5‐(4‐Pyridyl)‐4‐Aryl‐4H‐1,2,4‐Triazole‐3‐Thiols

The synthesis of some new S‐nucleosides of 5‐(4‐pyridyl)‐4‐aryl‐4H‐1,2,4‐triazole‐3‐thiols ( 4a‐n ) is described. Direct glycosylation of ( 4a‐n ) with tetra‐O‐acetyl‐α‐D‐glucopyranosyl bromide in the presence of potassium hydroxide followed by deacetylation using dry ammonia in methanol gave the corresponding 3‐S‐(ñ‐D‐glucopyranosyl)‐5‐(4‐pyridyl)‐4‐aryl‐4H‐1,2,4‐triazoles ( 6a‐n ) in good yields. All the compounds were fully characterized by means of ¹HNMR, ¹³C NMR spectra and elemental analyses. To assist in the interpretation of the spectroscopic data, the crystal structure of 3‐S‐(2′,3′,4′,6′‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl)‐5‐(4‐pyridyl)‐4‐phenyl‐4H‐1,2,4‐triazole ( 5a ) was determined by X‐ray diffraction.     

Synthesis of 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4′′‐hydroxyphenyl)‐thiazoles and their O‐glucosides

In continuation of our work, we synthesized 2‐(sulfamoylphenyl)‐4′‐amino‐4‐(4″‐hydroxyphenyl)‐thiazole ( 3a ), which were reacted with various (aryl/hetroaryl) aldehyde to form 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4″‐hydroxyphenyl)‐thiazoles ( 4a , 4b , 4c , 4d , 4e , 4f ). Glucosylation of compounds ( 4a , 4b , 4c , 4d , 4e , 4f ) have been done by using acetobromoglucose as a glucosyl donor to afford 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(2,3,4,6‐tetra‐O‐acetyl‐4″‐O‐β‐D ‐glucosidoxyphenyl)‐thiazoles ( 5a , 5b , 5c , 5d , 5e , 5f ), further on deacetylation to produce 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4″‐O‐β‐D ‐glucosidoxyphenyl)‐thiazoles ( 6a , 6b , 6c , 6d , 6e , 6f ). The compounds are confirmed by FTIR, ¹H‐NMR, ¹³C‐NMR, and ES‐Mass spectral analysis. J. Heterocyclic Chem., (2011).     

Bildung von 5,6-Dihydro-1,3(4H)-thiazin-4-carbonsäure-estern aus 4-Allyl-1,3-thiazol-5(4H)-onen

Formation of Methyl 5,6-Dihydro-l, 3(4H)-thiazine-4-carboxyiates from 4-Allyl-l, 3-thiazol-5(4H)-ones . The reaction of N-[1-(N, N-dimethylthiocarbamoyl)-1-methyl-3-butenyl]benzamid ( 1 ) with HCl or TsOH in MeCN or toluene yields a mixture of 4-allyl-4-methyl-2-phenyl-1,3-thiazol-5(4H)-one ( 5a ) and allyl 4-methyl-2-phenyl-1,3-thiazol-2-yl sulfide ( 11 ; Scheme 3). Most probably, the corresponding 1,3-oxazol-5(4H)-thiones B are intermediates in this reaction. With HCl in MeOH, 1 is transformed into methyl 5,6-dihydro-4,6-dimethyl-2-phenyl-1,3(4H)-thiazine-4-carboxylate ( 12a ). The same product 12a is formed on treatment of the 1,3-thiazol-5(4H)-one 5a with HCl in MeOH (Scheme 4). It is shown that the latter reaction type is common for 4-allyl-substituted 1,3-thiazol-5(4H)-ones.     

Bildung von 2-(1-Methyl-1, 4, 5, 6-tetrahydropyridyl-3)-2-oxazolin-4-on aus 1-Methyl-1, 4, 5, 6-tetrahydronicotinsäureamid und Bromessigsäureäthylester und seine Überführung in O-(1-Methylnipecotinoyl)glykolsäureamid via das dazu tautomere Cyclol

The main product of the reaction between 1-methyl-1, 4, 5, 6-tetrahydronicotin-amide and ethyl bromoacetate is shown to be the 2-(1-methyl-1, 4, 5, 6-tetrahydropyridyl-3)-2-oxazoline-4-one which on partial hydrogenation followed by reaction with alkali affords O-(1-methylnipecotinoyl)glycolic amide, presumably via the tautomeric cyclol.     

New domino‐reaction for the synthesis of N4‐(5‐aryl‐1,3‐oxathiol‐2‐yliden)‐2‐phenylquinazolin‐4‐amines and 4‐[4‐aryl‐5‐(2‐phenylquinazolin‐4‐yl)‐1,3‐thiazol‐2‐yl]morpholine

The model morpholine‐1‐carbothioic acid (2‐phenyl‐3H‐quinazolin‐4‐ylidene) amide (1) reacts with phenacyl bromides to afford N⁴‐(5‐aryl‐1,3‐oxathiol‐2‐yliden)‐2‐phenylquinazolin‐4‐amines (4) or N⁴‐(4,5‐diphenyl‐1,3‐oxathiol‐2‐yliden)‐2‐phenyl‐4‐aminoquinazoline ( 5 ) by a thermodynamically controlled reversible reaction favoring the enolate intermediate, while the 4‐[4‐aryl‐5‐(2‐phenylquinazolin‐4‐yl)‐1,3‐thiazol‐2‐yl]morpholine ( 8 ) was produced by a kinetically controlled reaction favoring the C‐anion intermediate. ¹H nmr, ¹³C nmr, ir, mass spectroscopy and x‐ray identified compounds ( 4 ), ( 5 ) and ( 8 ).     

Cyclische Carbonsäurephosphide

Cyclic Phosphides of Carbonic Acids 2-Organo-2-benzophospholen-1,3-dione have been prepared by the reaction of o? C₆H₄(COCl)₂ with Li₂PC₂H₅ or C₆H₅PH₂. Using disubstituted carbonic acid-chlorides the same reaction leads to indefinable products. 4-Butenoyl- and 5-Pentenoyl-phenyl- and -cyclohexylphosphines are produced from 3-butenoic and 4-pentenoic acid-chlorides and C₆H₅PH₂ or C₆H₁₁PH₂. These products are transferred to heterocyclic systems after addition of the P? H-group to the C? C-doublebond. By LiAlH₄ the phospholan-2-ones and phosphorinan-2-ones are reduced to the corresponding alcohols. The saponification of the parent compounds gives phosphino carbonic acids. The prepared P-heterocycles behave like ordinary tert. phosphines.     

Synthesis and reactivity of 2-polyfluoroalkylchromene-4(4<Emphasis Type="Italic">H</Emphasis>)-thiones

2-Polyfluoroalkylchromene-4(4H)-thiones, synthesized from 2-polyfluoroalkylchromones and P₂S₅, react with aniline, phenylhydrazines, and hydroxylamine at the C(4) atom and afford corresponding anils, phenylhydrazones, and oximes of chromones. On heating in alcohol in the presence of concentrated HCl, chromone phenylhydrazones and oximes undergo ring closure to form 3-(2-hydroxyaryl)-1-phenyl-5-polyfluoroalkylpyrazoles and 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-Δ²-isoxazolines.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2188–2195, October, 2004.     

CpPEt2As4—An Organic‐Substituted As4 Butterfly Compound

Cp^PEt₂As₄ (Cp^PEt=C₅(4‐EtC₆H₄)₅) ( 1 ) is synthesized by the reaction of Cp^PEt. radicals with yellow arsenic (As₄). In solution an equilibrium of the starting materials and the product is found. However, 1 can be isolated and stored in the solid state without decomposition. As₄ can be easily released from 1 under thermal or photochemical conditions. From powder samples of Cp^PEt₂As₄, yellow arsenic can be sublimed under rather mild conditions (T=125 °C). A similar behavior for the P₄‐releasing agent was determined for the related phosphorus compound Cp^BIG₂P₄ ( 2 ; Cp^BIG=C₅(4‐nBuC₆H₄)₅). DFT calculations show the importance of dispersion forces for the stability of the products.     

The Synthesis of (4E)‐N‐(4‐chlorophenyl)‐5‐substituted‐2‐diazo‐3‐oxopent‐4‐enoic Acid Amides

The (4E)‐N‐(4‐chlorophenyl)‐5‐(3‐chlorophenyl)‐2‐diazo‐3‐oxopent‐4‐enoic acid amides 5a˜j were synthesized with N‐(4‐chlorophenyl)‐2‐diazo‐3‐oxobutyramide 4 from p‐chloroaniline and various arylaldehydes. The yielded products 5a˜j were investigated with NMR, MS, IR, and X‐ray crystallographic techniques.     

4‐Aminopyridinium 4‐aminobenzoate dihydrate and 4‐aminopyridinium nicotinate

In the title compounds, 4‐aminopyridinium 4‐aminobenzoate dihydrate, C₇H₆NO₂⁻·C₅H₇N₂⁺·2H₂O, (I), and 4‐aminopyridinium nicotinate, C₅H₇N₂⁺·C₆H₄NO₂⁻, (II), the aromatic N atoms of the 4‐aminopyridinium cations are protonated. In (I), the asymmetric unit is composed of two 4‐aminopyridinium cations, two 4‐aminobenzoate anions and four water molecules, and the compound crystallizes in a noncentrosymmetric space group. The two sets of independent molecules of (I) are related by a centre of symmetry which is not part of the space group. In (I), the protonated pyridinium ring H atoms are involved in bifurcated hydrogen bonding with carboxylate O atoms to form an R₁²(4) ring motif. The water molecules link the ions to form a two‐dimensional network along the (10) plane. In (II), an intramolecular bifurcated hydrogen bond generates an R₁²(4) ring motif and inter‐ion hydrogen bonding generates an R₄²(16) ring motif. The packing of adduct (II) is consolidated via N—H...O and N—H...N hydrogen bonds to form a two‐dimensional network along the (10) plane.     

NMR studies on 4‐thio‐5‐furan‐modified and 4‐thio‐5‐thiophene‐modified nucleosides

Systematic NMR characterization of 4‐thio‐5‐furan‐pyrimidine nucleosides or 4‐thio‐5‐thiophene‐pyrimidine nucleosides (ribonucleosides and 2′‐deoxynucleosides) was performed. All proton and carbon signals of 4‐thio‐5‐thiophene‐ribouridine and related analogues were unambiguously assigned. The orientations of the base (4‐thiouridine or its deoxy analogue) relative to the ring (furan or thiophene) are explored by a NMR approach and further supported by X‐ray crystallographic studies. The procedures presented here would be applicable to other modified nucleosides and nucleotides. Copyright © 2016 John Wiley & Sons, Ltd.     

Photochemistry of 4‐ and 5‐ phenyl substituted isoxazoles

5‐Phenylisoxazole ( 4 ) and 4‐phenylisoxazole ( 22 ) underwent phototransposition to 5‐phenyloxazole ( 5 ) and 4‐phenyloxazole ( 24 ) respectively. Labeling with deuterium or methyl confirmed that these phototranspositions occurred via the P₄ pathway which involves only interchange of the N2 and C3 ring position. Thus, 4‐deuterio‐5‐phenylisoxazole ( 4‐4d ), 4‐methyl‐5‐phenylisoxazole ( 10 ), and 5‐methyl‐4‐phenylisoxazole ( 23 ) phototransposed to 4‐deuterio‐5‐phenyloxazole ( 5‐4d ), 4‐methyl‐5‐phenyloxazole ( 11 ), and 5‐methyl‐4‐phenyloxazole ( 25 ) respectively. In addition to phototransposition, isoxazoles 4, 10 , and 23 also underwent photo‐ring cleavage to yield benzoylacetonitrile (9), α‐benzoylpropionitrile ( 15 ), and aceto‐α‐phenylacetonitrile ( 26 ) respectively. Irradiation of 5‐phenyl‐3‐(trifluoromethyl)isoxazole ( 16 ) in acetonitrile led to 5‐phenyl‐2‐(trifluoromethyl)oxazole ( 17 ), the P₄ phototransposition product. Irradiation of 16 in methanol led to a substantial decrease in the yield of 17 and to the formation of a mixture of (E) and (Z)‐2‐methoxy‐2‐(trifluoromethyl)‐3‐benzoylaziridines 18a and 18b .     

Variationen modulo 4–4+, 4+3–3+4–, 4–5+, 5–4+4–5+4–4+ bei Seltenerdcarbidhalogeniden

The new compounds Pr₈(C₂)₄Cl₅ (1), Pr₁₄(C₂)₇Cl₉ (2), Pr₂₂(C₂)₁₁Cl₁₄ (3), Ce₂(C₂)Cl (4), La₂(C₂)Br (5), Ce₂(C₂)Br (6), Pr₂(C₂)Br (7), Ce₁₈(C₂)₉Cl₁₁ (8), and Ce₂₆(C₂)₁₃Cl₁₆ (9) were prepared by heating mixtures of LnX₃, Ln and carbon or in an alternatively way LnX₃, and “Ln₂C_3–x” in appropriate amounts for several days between 750 and 1200 °C. The crystal structures were investigated by X‐ray powder analysis (5–7) and/or single crystal diffraction (1–4, 8, 9). Pr₈(C₂)₄Cl₅ crystallizes in space group P2₁/c with the lattice parameters a = 7.6169(12), b = 16.689(2), c = 6.7688(2) Å, β = 103.94(1) °, Pr₁₄(C₂)₇Cl₉ in Pc with a = 7.6134(15), b = 29.432(6), c = 6.7705(14) Å, β = 104.00(3) °, Pr₂₂(C₂)₁₁Cl₁₄ in P2₁/c with a = 7.612(2), b = 46.127(9), c = 6.761(1) Å, β = 103.92(3) °, Ce₂(C₂)₂Cl in C2/c with a = 14.573(3), b = 4.129(1), c = 6.696(1) Å, β = 101.37(3) °, La₂(C₂)₂Br in C2/c with a = 15.313(5), b = 4.193(2), c = 6.842(2) Å, β = 100.53(3) °, Ce₂(C₂)₂Br in C2/c with a = 15.120(3), b = 4.179(1), c = 6.743(2) Å, β = 101.09(3) °, Pr₂(C₂)₂Br in C2/c with a = 15.054(5), b = 4.139(1), c = 6.713(3) Å, β = 101.08(3) °, Ce₁₈(C₂)₉Cl₁₁ in P$\bar{1}$ with a = 6.7705(14), b = 7.6573(15), c = 18.980(4) Å,α = 88.90(3) °, β = 80.32(3) °, γ = 76.09(3) °, and Ce₂₆(C₂)₁₃Cl₁₆ in P2₁/c with a = 7.6644(15), b = 54.249(11), c = 6.7956(14) Å, β = 103.98(3) ° The crystal structures are composed of Ln octahedra centered by C₂ dumbbells. Such Ln₆(C₂)‐octahedra are condensed into chains which are joined into undulated sheets. In compounds 1–4 three and four up and down inclined ribbons alternate (4₊4_–, 4₊3_–3₊4_–, 4₊4_–3₊4_–4₊3_–), in compounds 8 and 9 four and five (4₊5_–, 5₊4_–4₊5_–4₊4_–), and in compounds 4–7 one, one ribbons (1₊1_–) are present. The Ln‐(C₂)‐Ln layers are separated by monolayers of X atoms.     

Synthesis and reaction of 5,6,7,8‐tetrahydro‐4H‐oxazolo[4,5‐c]azepin‐4‐ones

The synthesis of 5,6,7,8‐tetrahydro‐4H‐oxazolo[4,5‐c]azepin‐4‐ones 5a,b and 1,3‐benzoxazol‐4‐amines 4a,b are described starting from 4,5,6,7‐tetrahydro‐1,3‐benzoxazol‐4‐ones. Thionation of 5a,b followed by alkylation with ethyl bromoacetate led to the corresponding S‐alkyl azepines 7a,b .     

Synthesis of 3‐(4‐Oxo‐4H‐quinolizinyl‐3) and 3‐(4‐Oxo‐4H‐pyridino[1,2‐a]pyrimidinyl‐3) substituted lactic acid derivatives

A one‐step ‘ring switching’ transformation of (S)‐3‐[(dimethylamino)methylidene]‐5‐(methoxycarbonyl)tetrahydrofuran‐2‐one ( 4 ) with 2‐pyridineacetic acid derivatives ( 5–7 ) and 2‐aminopyridines ( 8, 9 ) afforded the corresponding 3‐(4‐oxo‐4H‐quinolizinyl‐3)‐ (15–17) and 3‐(4‐oxo‐4H‐pyridino[1,2‐a]pyrimidinyl‐3)‐2‐hydroxypropanoates ( 18, 19 ), respectively.     

Beiträge zur Chemie der 4-Hydroxyindol-Verbindungen 10. Mitteilung über synthetische indolverbindungen [1]

Catalytic hydrogenation of 4-benzyloxyindoles does not stop at the hydroxyindole stage, but slowly leads to the 4,5,6,7-tetrahydro-4-ox-indoles 3 . Some procedures for the selective preparation of 4-hydroxyindoles 2 are described. When 4-benzyloxy-3-(1-hydroxyimino-ethyl)-indole ( 4c ) is warmed with trifluoroacetic acid, cleavage of the ether results as well as partial benzylation of the free hydroxyindole in the position 5 ( 5a, 5b ); no Beckmann rearrangement is observed. Esters of 4-benzyloxy-indole-2-carboxylic acid are formylated with POCl₃/dimethylformamide in the 7-position to give 7a ; in the corresponding dimethylamide, on the other hand, the formyl group enters the 3-position to give 8 . Both 4- and 7-hydroxyindole are oxidized with Frémy's salt to the 4, 7-quinone 13 ; on reduction this yields 4, 7-dihydroxyindole 14 , which is tautomerized by base-catalysis to 5, 6-dihydro-4, 7-dioxo-indole 15 . The course of the etherification of 4-hydroxyindoles with epichlorohydrin and related compounds is described, and the resulting side-chains are characterized by their NMR. spectra.     

Energetic Derivatives of 4, 4′,5, 5′‐Tetranitro‐2, 2′‐bisimidazole (TNBI)

4, 4′,5, 5′‐Tetranitro‐2, 2′‐bisimidazole (TNBI) was synthesized by nitration of bisimidazole (BI) and recrystallized from acetone to form a crystalline acetone adduct. Its ammonium salt ( 1 ) was obtained by the reaction with gaseous ammonia. In order to explore new explosives or propellants several energetic nitrogen‐rich 2:1 salts such as the hydroxylammonium ( 3 ), guanidinium ( 4 ), aminoguanidinium ( 5 ), diaminoguanidinium ( 6 ) and triaminoguanidinium 7 4, 4′,5, 5′‐tetranitro‐2, 2′‐bisimidazolate were prepared by facile metathesis reactions. In addition, methylated 1, 1′‐dimethyl‐4, 4′,5, 5′‐tetranitro‐2, 2′‐bisimidazole (Me₂TNBI, 8 ) was synthesized by the reaction of 2 and dimethyl sulfate. Metal salts of TNBI can also be easily synthesized by using the corresponding metal bases. This was proven by the synthesis of pyrotechnically relevant dipotassium 4, 4′,5, 5′‐tetranitro‐2, 2′‐bisimidazolate ( 2 ), which is a brilliant burning component e.g. in near‐infrared flares. All compounds were characterized by single crystal X‐ray diffraction, NMR and vibrational spectroscopy, elemental analysis and DSC. The sensitivities were determined by BAM methods (drophammer and friction tester). The heats of formation were calculated using CBS‐4M electronic enthalpies and the atomization method. With these values and mostly the X‐ray densities different detonation parameters were computed by the EXPLO5 computer code. Due to the great thermal stability and calculated energetic properties, especially guanidinium salt 4 could be served as a HNS replacement.     

Bildung und Verhalten von Chlorozinksäuren in äthanolischer Lösung

Formation and Behaviour of Chlorozinc Acids in Ethanolic Solution The reaction between ZnCl₂ and HCl in ethanol leads to H₂ZnCl₄ only. The behaviour of H₂ZnCl₄ · 3 (C₂H₅)₂O, (NH₄)₂[ZnCl₄] and HCl in ethanolic solutions has been investigated by means of conductivity measurements at ?10 and ?20°C. The equivalent conductivities have been determined. The Stokes radii of [ZnCl₄]^2?, H⁺, and [(C₂H₅)₂OH]⁺ are calculated.