Reaktionen mit N-Acylimino-dithiokohlensäurediestern

Reactions with N-Acylimino-dithiocarbonic-acid-diesters . Reactions of N-acylimino-dithiocarbonic-acid-S,S-diesters 1 with nucleophilic com-pounds present new possibilities to synthesize heterocycles. With amines 1a reacts by mono- and disubstitution, respectively, of methylthio-groups to isothioureas 2 and guanidines 3 , with 1,2-bi-nucleophilic arenes to benzoheterocycles 4 , with aliphatic diamines to imidazolidines 5 , pyrimidines 6 , diazepines 7 and the hexamethylene-diamine-derivatives 8. 1a reacts also with hydrazines to 1,2,4-triazoles 9 and with hydrazides to the thiosemicarbazones 10 or 1,3,4-oxadiazoles 11 . Heterocyclisations of 1 with guanidines, thiourea, salts of thiourea and amidines give the 1,3,5-triazines 12, 14, 15 and 16 . N-benzoyl-dithiocarbonic-acid-methylester -amid reacts with CH-acidic compounds to thiazoles 17 . The structures of the final products are determined by i.r.-, ¹H-n.m.r.-, u.v.- and mass-spectras.     

Reaktionen von Aroyl(Hetaroyl)iminodithiokohlesäureestern mit Carbanionen CH-acider Verbindungen

Reactions of Dimethyl N-Aroyl(Hetaroyl)carbimidodithioates with Carbanions CH-acidic Compounds Reactions of dimethyl N-aroyl(hetaroyl)carbimidodithioates 1 with carbanions 2 present new possibilities to synthesize 3-acyl-amino-3-methylthio-2-subst.-acrylnitriles 3 by monosubstitution of methylthiogroup. The reaction of 1 with 2-alkyl-benzothiazolium salts 4 yield deeply coloured N-acyl-(2,3-dihydrobenzothiazole-2-yliden) thioacetimido acid-methylates 5 of the 2-subst.-benzothiazoliumperchlorates 6 . The structures of the final products are determined by i.r.-, ¹H.-n.m.r.- and u.v.-spectra.     

Zur Chlorierung von N-Aryl-2,4-dimethyl-buta-1,3-dien-1,4-sultamen

About Chlorination of N-Aryl-2,4-dimethyl-buta-1,3-dien-1,4-sultames The sultames of structure 1 are easily chlorinated by sulfurylchloride, chlorine or tertbutylhypochlorite. The structure of the mono-( 2a-c,3a, d ), di-( 4a-d ), tri- ( 5c, d ) and pentachlorosultames ( 6a, b ) is determined by ¹³C-n.m.r. spectroscopy. Contrary to the bromination the chlorination (by SO₂Cl₂) starts with the substitution of the sultamring (formation of mono- and di-chlorosultames) followed of the substitution of the (C-4)-CH₃- group (formation of trichlorosultames). By 1,4-addition of an other molecule of chlorine to 5 the pentachlorosultames 6a, b are obtained. Already by recrystalisation of 6a, b in an alcohol the chlorine in 4-position is exchanged by the corresponding alkoxy group (CH₃O, C₂H₅O, n-C₃H₇O) and the compounds 7-9 are formed.     

Synthesis and characterization of some long-chain diesters with branched or bulky moieties

Several novel fatty diesters with bulky moieties were synthesized by esterification of mono- or bifunctional fatty acids or with mono- or bifunctional alcohols using p-toluenesulfonic acid as catalyst. They were characterized by ¹H and ¹³C nuclear magnetic resonance as well as positive chemical ionization (PCl) mass spectrometry. The PCl mass spectra of the resulting diol diesters and diacid diesters are discussed and compared. The compounds were investigated as potential additives for improving the cold flow properties of vegetable oil esters used as biodiesel. Retired.     

α-Substituierte Phosphonate. XXXIV. Zur Veresterung und N-Formylierung von α-Aminomethan-bisphosphonsäuren mit Orthoameisensäuretriethylester

α-Substituted Phosphonates. XXXIV. Esterification and N-Formylation of α-Aminomethane-bisphosphonic Acids with Triethylorthoformate In contrast to simple mono- and bisphosphonic acids esterification of dialkylaminomethanebisphosphonic acids with orthoformate (OAE) proceeds very slowly. Monoalkyl and monoarylaminomethanebisphosphonic acids, respectively react with OAE in constrast to analogous hydroxy compounds more readily primarily by formylating the N-atom and then esterification to formyl aminomethane bisphosphonictetraesters 10 . Acetaminomethanephosphonic acid ( 12 ) reacts without N-formylation, while the aminomethanebisphosphonic acid ( 14 ) reacted to give a mixture of mono- and bis-formylated products 15 and 16 . By acidic hydrolysis of 10 the ester- and formylgroups are splitt off, while the ester group can selectively be removed by reaction with Me₃SiBr/H₂O. – As shown by ¹H-, ¹³C- and ³¹P-n.m.r. spectroscopy the phosphorylated formamides 10 exists in two rotameres, the ratio depending on the solvent. The n.m.r. signals could be correlated to E-resp. Z-form undoubtedly by using shift-agents or the benzene-diluting technique. A rotational barrier of 22,8 kcal for 10c could be calculated.     

A review on the chemistry,coordination, structure and biological properties of 1-(acyl/aroyl)-3-(substituted) thioureas

This review provides an overview of the chemistry, structure and potential applications of 1-(acyl/aroyl)-3-(mono-substituted) and 1-(acyl/aroyl)-3,3-(di-substituted) thioureas, with general formula R¹C(O)N₍₁₎HC(S)N₍₃₎R²R³. In recent years, the title compounds have found extensive applications as ligands in coordination chemistry. The effect that nitrogen substituents exert on the intra- and intermolecular hydrogen-bonding interactions is discussed, including their role on the coordination properties displayed by these ligands. Novel applications of transition metal complexes bearing 1-(acyl/aroyl)-3-(mono- and di-substituted) thioureas are introduced. Biological aspects are also highlighted. As recently demonstrated, high-throughput screening assay and structure–activity analyses are feasible for this class of compounds. The chemical versatility of 1-(acyl)-3-(substituted) thiourea molecules and the derived metal complexes, together with the possibility of determining detailed structural properties, join biological applications in a promising interdisciplinary approach. The bibliography includes 382 references with emphasis on the literature appearing after 2007.     

Products of the Reaction Between Alcohols and Phosphorus Pentoxide. III. Identification by Infrared Spectrophotometry

The various compounds obtained by the reaction P₄O₁₀ + 4ROH (where R represents hydrocarbon radicals of various length and structure) were identified by infrared spectrophotometry of the fractions separated by column chromatography. The identification was made possible by a comparison between the relative values of the integrated absorption for the P = O, P-O-P, P-O-C and O-H bands with those of known standards. For the reaction of phosphorus pentoxide with ethanol, the compounds formed were found to be: mono-, di- and triethyl phosphate, mono-, (1, 2) di- and triethyl-pyrophosphate; (1, 3) di- and (1, 2, 3) triethyl triphosphate; mono- and diethyl trimetaphosphate. With other alcohols, only homologs of these compounds were found, but always fewer compounds. Uncertainty between possible isomers was resolved by identification of their acid hydrolysis products.     

Synthese von cyclischen N,O- bzw. N,S-Heterocyclen durch Kondensation von Fettsäurealkylolamiden mit Carbonylverbindungen bzw. Phosphorpentasulfid

Synthesis of Cyclic N,O- and N,S-Heterocyclic Compounds by Condensation of Fatty Acid Alkylolamides with Carbonyl Compounds and Phosphorous Pentasulfide Respectively Fatty acid alkylolamides of the type RCONHCHR¹ (CH₂)_n CHR₂OH (R: alkyl rest with 2 to 17 carbon atoms, cycloalkyl or aryl rest; R₁ and R₂: alkyl rests with 1 to 3 carbon atoms or hydrogen; and n = 0–2) are converted by acidic condensation with lower aliphatic or aromatic aldehydes and ketones respectively to mono- and disubstituted N-acyl-oxazolidines, N-acyl-1,3-tetrahydrooxazines and N-acyl-1,3-hexahydrooxazepines. Furthermore, new types of 2-alkyl-4,5-dihydro-6H-1,3-thiazine (n = 1) besides monoalkyl substituted Δ-2-thiazolines (n = 0) were obtained from fatty acid alkylolamides by condensation with P₂S₅. A large number of the compounds prepared show excellent bacteriostatic and fungistatic action.     

Reaction of CH-acidic compounds with thiacumulenes and alkylation with dihaloalkanes

Dithiocarboxylation of CH-acidic compounds 1 and stepwise alkylation of primarily formed dithiolates 2 yielded ketene dithioacetals 5a,b or methylenebis(dithiocarbonates) 12a–c. Reaction of 5a,b with nucleophiles afforded thiophene 7 and dithioacetals 8, 9a,b, 11, respectively. 1,3-Thiazetidines 14a,c,e and thiazolidines 14b,d,f were prepared by thiocarbamoylation of 1b,c,e and subsequent alkylation with dihaloalkanes.     

Synthesis and crystal structures of mono-, bis- as well as tris-mercurated complexes with ferrocenylazines

The mono-(cyclomercurated) complex (2) and bis-(cyclomercurated) complexes (3) as well as the first example of a tris-mercurated ferrocenylimine (4) have been conveniently prepared from the reaction of ferrocenylazines (1) with Hg(OAc)₂ and subsequent treatment with LiCl. All the new compounds were characterized by elemental analysis, ¹H NMR and IR spectra. X-ray single crystal analysis confirms that complex 2 exists as a tetramer in the crystal due to intermolecular bridged Cl–Hg bonds and weak intermolecular N–Hg coordination. While 3b and 4 have a one-dimensional chain structure formed by intermolecular bridged Cl–Hg bonds and CH(Cp)⋯Cl hydrogen bonds.     

Addition of bisulfite to α-olefins: Synthesis of n-alkane sulfonates and characterization of intermediates

The free radical-catalyzed bisulfite addition to octene-1, decene-1, dodecene-1 and tetradecene-1 was studied under different conditions. The experimental conditions could be adjusted to yield different ratios of intermediate as well as final compounds. We have separated, purified and positively identified alkane-1-sodium sulfonates of general formula CH₃-(CH₂)_n-SO₃Na (n=7,9,11 and 13), alkane-1-sodium sulfonate-2-sulfinic acids of general formula CH₃-(CH₂)_n-CHSO₂H-CH₂-SO₃Na (n=5,7,9 and 11) and alkane-1,2-disodium sulfonates of general formula CH₃-(CH₂)_n-CHSO₃Na-CH₂-SO₃Na (n=5,7,9 and 11). The solubilities and critical micelle concentrations of mono- and disodium alkane sulfonates were determined, and for definite identification¹³C nuclear magnetic resonance (NMR) and dispersive X-ray crystallography were employed along with classical wet analytical procedures.     

Synthesis of end-functionalized polymer by means of living anionic polymerization. 4. Synthesis of polyisoprene and polystyrene with epoxy termini by reaction of their anionic living polymers with 2-bromoethyloxirane

In order to synthesize ω-epoxy-functionalized 1,4-polyisoprene ω-epoxy- and α,ω-diepoxy-functionalized polystyrenes, anionic living polyisoprene and polystyrene were allowed to react with excess amounts of 2-bromoethyloxirane in THF at ?78°C. The resulting polymers were analysed by SEC, ¹H and ¹³C NMR spectroscopy, and thin layer chromatography with flame ionization detection (TLC–FID). Both mono- and di-epoxy terminated polymers of controlled molecular weights (2.5 × 10³?2.6 × 10⁴ g/mol) and of narrow molecular weight distributions were obtained quantitatively with high functionalities.     

Rapid quantitative determination by 13C NMR of the composition of acetylglycerol mixtures as byproduct in biodiesel synthesis

Commercially available partly acetylated glycerols (mono- and diacetin) are mixtures of glycerol, 1- and 2-acetylglycerol, 1,2- and 1,3-diacetylglycerol, and triacetin. Diacetin and monoacetin are by-products of the biodiesel and triacetin production using glycerol esterification with acetic acid or triglyceride interesterification with methyl acetate. Usually, primary analytical methods involve chromatography (HPLC or GC), spectroscopy (MS or NIR), and wet chemical techniques (potentiometric, iodometric titration) which are often time-consuming due to sample preparation, extended analysis time and/or complicated data analysis. Moreover, these methods require pure mono- and diacetin as standard, which are commercially unavailable.In this work, a complete ³¹P and ¹³C chemical shift data for glycerol, mono-, di- and triacetin (including isomers) allows for the identification and quantification of these components in the commercial mixtures. This experimental protocol allows for rapid analysis of mixtures that include these six components. Quantitative ³¹P NMR and ¹³C NMR results were validated to those obtained with other analytical methods, such as GC and HPLC-ELSD. ¹³C NMR is preferred due to allows to measure the content of triacetin, which has no free hydroxyl group, and no signal was detected by ³¹P NMR.     

Synthesis of macrocyclic phenanthrolines with exotopic binding sites. Probing their complexation behavior with copper(I) and iron(II)

Starting from 4,7-dichlorophenanthroline ( 1 ) a synthetic approach is developed to novel macrocyclic mono- and bisphenanthrolines ( 5a – d , 6a – d ) with exotopic binding sites. As these coordinating compounds are characterized by a flexible spacer unit, their utility as ligand for the construction of oligomeric, dendritic and box-like structures in the presence of copper(I) and iron(II) is evaluated. Spectroscopic data suggest that with copper(I) the [1+1] adduct [Cu₂( 6c )( 7 )]²⁺ is formed.     

Synthesis of a New Type of Water-Soluble Phosphines by addition of hydrophilic thiols to vinylphosphines. Preparation of the rhodium and palladium complexes

Commercially available ω-thioalkane sodium sulfonates could easily be added to mono-, bi- and trivinylphosphines. The two-phase system became homogeneous by stirring. The products (1–6, 11) were characterized as phosphinoethyl-sulfonatoalkyl-thioethers with an unexpected high water solubility and with defined P/S ratios from 1/2, 1/4 and 1/6. All thioetherphosphines were characterized by ¹H, ¹³C and ³¹P NMR spectroscopy, IR spectroscopy and elemental analysis. Addition occurs only at pH > 7 and in the absence of strong electrophiles to avoid the formation of phosphonium compounds. L -Cysteine ethyl ester (8) and 2-aminoethanethiol (9) react exclusively at the thiol group. The first complexes with Pd(II), Rh(III) and Rh(I) show a participation of the thioether group in the coordination.     

Chitosan N-benzyl sulfonate derivatives as sorbents for removal of metal ions in an acidic medium

We synthesized chitosan-based sorbents for the uptake of metal cations in acidic solutions. Chitosan was reacted with 2-formylbenzene sodium sulfonate and 4-formyl-1,3-benzene sodium disulfonate in the presence of NaCNBH₃ to yield N-benzyl mono- and disulfonate derivatives of chitosan. IR and NMR spectra confirmed the presence of benzyl sulfonate groups. The degrees of substitution of the monosulfonate chitosan derivatives were in the range of 80%, while those of disulfonate derivatives were about 50%. These sulfonate derivatives of chitosan were tested on the sorption of heavy metals Cd²⁺, Zn²⁺, Ni²⁺, Pb²⁺, Cu²⁺, Fe³⁺, and Cr³⁺. The sorption capacities for disulfonate compounds were better than for monosulfonate compounds. This phenomenon was attributed to the amphoteric character of the monosulfonate derivatives. To improve the capacity of adsorption of monosulfonate compounds, the amino groups of these compounds were protected by the benzyloxycarbonyl groups. The protection of amino groups of disulfonate derivatives by benzyloxycarbonyl also improved their sorption capacity. The resulting protected polymers were tested for sorption of heavy metals. Both protected polymers were more efficient than are the parent nonprotected polymers. The synthesized sulfonate derivatives of chitosan are especially adapted to the sorption of heavy metals from the acidic industrial effluents. © 1996 John Wiley & Sons, Inc.     

A mononuclear copper(II) complex of a protonated unsymmetrical dinucleating Schiff base ligand

Reaction of the unsymmetrical and potentially dinucleating Schiff base ligand HL¹ with copper(II) salts has given mono- and dinuclear metal complexes. The structure of a mononuclear complex of diprotonated HL¹, [Cu(H₂L¹)(OH₂)](ClO₄)₃·H₂O·CH₃OH_, has been determined.     

Eine neue Synthese des Cinnamoyliminodithiokohlensäure-S,S-dimethylesters und Umsetzungen mit Nucleophilen

New Synthesis of Dimethyl-cinnamoylimino-dithiocarboxylate and Reactions with Nucleophiles A new general synthesis of dimethyl-cinnamoylimino-dithiocarboxylate 1d is possible by reaction of 4-nitro-cinnamoylamide with carbon disulfide in the presence of sodium hydride and following alkylation. With the unsubstituted dimethyl-cinnamoylimino-dithiocarboxylate 10 is in-vestigated the reaction behavior with nucleophilic compounds. The treatment of 1c with primary amines, respectively, by mono- and disubstitution of the methylthio groups yields isothiourea 2 or guanidines 3 . Benzocondensed heterocycles are formed by reaction of 1c with o-bifunctional nucleo-philes. The compounds 5, 6 and 7 have been synthesized from 1c with cysteamine, p-phenylenediamine and ethylenediamine. The oxadiazole 8 and isothiosemicarbazide 9 are obtained by reaction of the dithioester 1c with hydrazides. On the other hand cyclisation to the 1,2,4-triazole 11 over the intermediate 10 and to the 1,3,5-triazine 12 are possible. The reaction of 1c with carbanions in a basic medium affords acrylic derivatives 13 . In the same way we isolated by reaction of dithioester 1c with a benzothiazolium salt the dark coloured compound 14 . The physical properties of synthesized compounds are discussed by mass-, ¹H-n.m.r.-, i.r.- and u.v.-spectra.     

Radikalreaktion an N-Heterocyclen. XIII. Oxidation cyclischer Hydrazoverbindungen mit 2,4,6-Tri-tert-butyl-phenoxyl und Folgereaktionen der Radikalkombinationsprodukte

Free Radical Reactions of N-Heterocyclic Compounds. XIII. Oxidation of Cyclic Hydrazo Compounds with 2,4,6-Tri-tert-butyl-phenoxy Radical and Reactions of Radical Combination Products N-Heterocyclic compounds 1a, b containing the hydrazo structure were oxidized with 2,4,6-tri-tert-butyl-phenoxy radical ( 2 ). It was shown that the oxidation did not lead to the azo compounds 5a, b , but rather to radical combination products 6a, b of 2 via the intermediate hydrazyls 4a, b . The decomposition of adducts 6a, b was found to be similar to the reaction of radical combination products of aryl hydrazyls and CH-acidic compounds. The main reactions consisted of cleavage to starting radicals or elimination of isobutene forming the respective phenolic compounds 13a–c .     

Asymmetric distribution of decanoate in triacylglycerol synthesized in vitro by mammary glands of lactating mice

Slices, prepared from the mammary glands of lactating mice, were incubated with either [1-¹⁴C]acetate, [U-¹⁴C]glucose, or [1-¹⁴C]decanoate. From all 3 substrates, radioactivity in the synthesized lipids was found mainly in triacylglycerols (TG). When acetate or glucose served as substrate, decanoate (C₁₀) accounted for 24% of the fatty acids in TG. Hydrolysis of the TG by pancreatic lipase yielded [¹⁴C] fatty acids which had relatively more C₁₀ (38%) than did either of the other hydrolysis products mono- or diacylglycerol (14–17%). However, when TG produced by slices from C₁₀ were hydrolyzed, the acid was found to be esterified equally at the C-1, C-2 and C-3 of glycerol. Thus, when fatty acids are synthesized de novo and are converted to TG by gland slices, C₁₀ is predominantly located in the C-3 position, a finding in accord with the situation in milk TG, although such preferential incorporation does not occur when the free acid is presented to the tissue slices.