Aliphatic Azides Research Articles

NO donors with antithrombotic and vasodilating activities, Part 23. Organic azides.

Twenty eight organic azides were synthesized and tested for their antithrombotic and blood pressure lowering activities in rats (60 mg/kg, p.o.). In fifteen compounds significant antithrombotic effects were observed. In thirteen cases a significant lowering of the blood pressure of spontaneously hypertensive rats (SHR) was seen. The peak activities in both systems were found for hexyl azide (4), 2-phenylethyl azide (14), and 4-pyridinecarboxylic acid azide (23). In these compounds the inhibition of thrombus formation in mesenteric arterioles was > 20%. The lowering of blood pressure was > 10% and long lasting (> 6 h) in 4 and 14 while 23 had a shorter duration of action (approximately 4 h). In two classes of azides, namely branched aliphatic azides (e.g. 2-azidopentane 9) and aliphatic carbonyl derivatives (e.g. benzoyl-azido-methane 17), only antithrombotic properties were observed. A lack of endothelial metabolism is suggested to be the reason for this therapeutically favorable behaviour.

Reducing Characteristics of Borohydride Exchange Resin–CuSO4 in Methanol

Abstract Reducing characteristics of borohydride exchange resin (BER)–CuSO4 (cat.) were studied in methanol at room temperature. Carbon–carbon double bonds conjugated with benzene or carbonyl group were more rapidly reduced than was the case with isolated double bonds. Carbonyl groups were readily reduced, whereas esters and amides were inert, and nitriles were slowly reduced. High chemoselectivity was also observed in halide reductions: p-bromochlorobenzene and p-bromoiodobenzene were reduced quantitatively to chlorobenzene and bromobenzene, respectively. Aliphatic epoxides were inert to this reagent; however, styrene oxide derivatives were readily reduced to the corresponding deoxygenated products. Aliphatic azides were reduced slowly during 6 h, whereas phenyl azide was transformed to aniline in 1 h. Nitrocyclohexane was reduced at room temperature, but nitrobenzene, nitrosobenzene, azobenzene, and azoxybenzene required an elevated temperature (65 °C) for rapid reductions (1 h). Similarly, N,N-dimethylaniline N-oxide was reduced at room temperature, whereas pyridine N-oxide required refluxing. Finally, among the sulfur compounds tested, only diphenyl disulfide was reduced readily, and sulfide, aliphatic disulfide, sulfoxide, sulfone, and tosylate were inert to this reducing system.

ChemInform Abstract: Aliphatic Azides as Lewis Bases. Application to the Synthesis of Heterocyclic Compounds

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Aliphatic azides as lewis bases. Application to the synthesis of heterocyclic compounds

Aliphatic azides as lewis bases. Application to the synthesis of heterocyclic compounds

ChemInform Abstract: Synthesis of Amines by the Intermolecular Schmidt Reaction of Aliphatic Azides with Carbocations.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Amines by the Intermolecular Schmidt Reaction of Aliphatic Azides with Carbocations

Synthesis of Amines by the Intermolecular Schmidt Reaction of Aliphatic Azides with Carbocations

Aminoborohydrides. 8. A facile reduction of aliphatic and benzylic azides to the corresponding amines in high yield and purity using lithium N, N-dimethylaminoborohydride

Lithium N,N-dimethylaminoborohydride (LiMe 2NBH 3) reduced both 3α-azidocholest-5-ene and 3β-azidocholest-5-ene in air to give the corresponding 3α-aminocholest-5-ene and 3β-aminocholest-5-ene in 98% isolated yields. Aliphatic and benzylic azides were also reduced with LiMe 2NBH 3 to give the corresponding amines in isolated yields ranging from 85 to 98%. The reductions were complete in 1–3 hours and required only a simple acid-base extraction to isolate the desired amines.

ChemInform Abstract: Intramolecular Schmidt Reactions of Azides with Carbocations: Synthesis of Bridged‐Bicyclic and Fused‐Bicyclic Tertiary Amines.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reduction of Azides to Amines with Borohydride Exchange Resin – Nickel Acetate

Abstract Borohydride exchange resin (BER) - nickel acetate system in methanol readily reduces both aliphatic and aromatic azides to the corresponding amines in excellent yields.

Aliphatic amino azides as key building blocks for efficient polyamine syntheses

New routes to open-chain polyamines have been developed using aliphatic amino azides as common precursors for the construction of the carbon-nitrogen framework. These α,ω-diaminoalkane synthetic equivalents were combined with (ω-halogenoalkyl)dichloroboranes to extend the polyamine chain from the azido moiety. An extension from the free amino group can also be achieved via a Michael type addition with acrylonitrile or a reductive amination with a γ-azido ketone. Further transformations led to a large variety of regioselectively C- or (and) N-substituted polyamines

UVPES of some aliphatic azides Part III

Ab initio SCF calculations for 2-chloroethyl azide (ClCH 2CH 2N 3), ethyl azidoacetate (N 3CH 2COOC 2H( 5) and 3-azido-2-butanone (CH 3CHN 3COCH 3) were performed in order that their UV photoelectron spectra could be reliably interpreted. Good agreement was found when comparing the ionisation energies given by the calculations with the bands of the photoelectron spectra of the above mentioned molecules.

UVPES of some aliphatic azides. Part II

UVPES of some aliphatic azides. Part II

The intramolecular cycloaddition of azides with ω-chloroalkenes. A facile route to (±)-swainsonine and other indolizidine alkaloids

A potentially general route to the 1-azabicyclo[n.m.O]alkane skeleton of various alkaloids is embodied in the intramolecular 1,3-dipolar cycloaddition of aliphatic azides with ω-chloroalkenes. Cycloaddition is followed by rearrangement and intramolecular N-alkylation, affording bicyclic iminium ions 1 in one operation. The application of this method to the synthesis of (±)-δ-coniceine 6, (1S,2R,8aR)-indolizidine-1,2-diol 13 and (−)-swainsonine 15 is described.

UVPES of some aliphatic azides. Part I

Ab-initio calculations for ethyl azide-CH 3CH 2N 3- and azidoacetone-N 3CH 2COCH 3-were performed with the aim of interpreting their ultraviolet photoelectron spectra. Some preliminary results are presented. The first bands of the photoelectron spectra of the azides under study are intense and sharp indicating ionization from a non-bonding orbital. This is in accordance with the performed calculations, which also predict a non-bonding character to the molecular orbitals corresponding to the first ionization energies. Good agreement was also found when comparing the second ionization energies given by the calculations with the second bands of the photoelectron spectra of the molecules.

New Synthetic “tricks”. [Et 3NH][Sn(SPh 3)] and Bu 2SnH 2, two useful reagents for the reduction of azides to amines

Sn(SPh) 3 − azides (either primary, secondary, or tertiary; either aliphatic, aromatic, or heteroaromatic) very quickly. Bu 2SnH 2 is also useful in this connection. A scale of reducing power, with regard to aliphatic azides, has been established

ChemInform Abstract: Investigations of Vinylic Azides. Part 5. Cathodic Reduction of Aliphatic Azides and of Azides, Activated by Olefinic and Carbonyl Groups.

AbstractRetention of one nitrogen of the azide group in most of the products obtained by the reduction of (I), (IV), (VI), or (X) leads to novel amine or stabilized enamine derivatives.

Cyclisierung und fragmentierung aliphatischer azide an metall-metall-dreifachbindungen: Neuartige reaktionswege gegenüber ihrer thermischen zersetzung ln der gasphase [1,2

The organoazides 4a–4c react with the dinuclear molybdenum and tungsten compounds of composition [(η 5-C 5R 5)M(CO) 2] 2 (R = H, M = Mo: 1; CH 3, Mo: 2; CH 3, W: 3) at temperatures between 200 and 300 K to yield the novel organoimido derivatives 5–7 in quantitative yields. The dominating structural characteristics of the products are fused 3 5 -membered metallacycles that originate from addition of the aliphatic azides to the metal-metal multiple bonds of the precursor organometallics 1-3 with consecutive ring closure via nucleophilic attack of the coordinated azide upon one of the metalcarbonyl ligands. Another azide molecule undergoes metal-induced nitrogen elimination, with the remaining organoimido fragment being coordinated as a linear terminal ligand through a molybdenum-nitrogen triple bond (172.6(9) pm). The thermal decomposition of allyl azides monitored in the gas phase by the changes in photo-electron spectroscopic ionization patterns, underlines the dominating effect of the multiply bonded metalmetal coordination sphere: N 2 is eliminated only at temperatures above 650 K. As exemplified for allyl azide, the red-hot tube pyrolysis is dominated by a 1,2-hydrogen shift accompanying the N 2 elimination and yields the corresponding imine, H 2CCHC(H)NH.

Reactions of the nitrosonium ion. 11. Fluoride transfer from complex fluoride anions to carbenium ions in the nitrosative decomposition of aliphatic azides

Reactions of the nitrosonium ion. 11. Fluoride transfer from complex fluoride anions to carbenium ions in the nitrosative decomposition of aliphatic azides

Sulfonylierungs- und Aminierungsreaktionen von Sulfonsäureaziden.

The reaction of aromatic and aliphatic sulfonic azides with benzene under the influence of aluminiumchloride has been examined. The intermolecular substitution reactions - sulfonylation, amination and alkylation - are dependent from the structural effect of the corresponding substituent

Thermochemistry and reactivity of the azides - II. Lattice energies of ionic azides, electron affinity and heat of formation of the azide radical and related properties

The thermochemical data of part I, the heats of formation and solution of the alkali-metal (group 1 a ) azides, are used in conjunction with other data to derive values for the lattice energies of alkali-metal azides, the heat of formation of the azide radical, for the electron affinity and hydration heat of the azide ion. Calculations by previous workers of these magnitudes, which are not of course susceptible to direct measurement, have generally been erroneous. The lattice energies of the alkali azides (kcal mole -1 ) are: LiN 3 , 194; NaN 3 , 175; KN 3 , 157; RbN 3 , 152; CsN 3 , 146. For potassium, rubidium and caesium azides a term-by-term theoretical calculation of the lattice energy which allows for the non-spherical character of the azide ion supports these figures, which are based on experimental data of part I. The standard enthalpy of formation of the azide radical ∆ H 0 f (N 3G ) is estimated to be 116 kcal mole -1 . The electron affinity of the azide radical E (N 3G ) is 81 kcal mole -1 . These figures permit the evaluation of other lattice energies and the following values (kcal mole -1 ) have been obtained: NH 4 N 3 , 175; CuN 3 , 227; AgN 3 , 205; TlN 3 , 163·5; CaN 6 , 517; SrN 6 , 494; BaN 6 , 469 and PbN 6 , 516. From the enthalpy of formation of the azide radical the bond dissociation energies D ( X — N 3 ) in some covalent azides may be derived. D (H — N 3 ) is 96 kcal mole -1 and D (C— N 3 ) in aliphatic azides is about 83 kcal mole -1 .