An Efficient Synthesis of [15N]-Carbazole from [15N]-Aniline

A reaction sequence involving ortho-lithiation of [¹⁵N]-(tert-Butoxy-carbonyl)aniline, quenching with Bu₃SnCl, palladium catalyzed coupling with bromobenzene, and deprotection provides efficient access to [¹⁵N]-2-aminobiphenyl (4). Compound 4 is converted to [¹⁵N]-carbazole via diazotization, treatment with NaN₃, and heating to promote intramolecular nitrene insertion.     

Reaction of dichloroketene and sulfene with N,N-disubstituted 6-amino-methylene-b,7,8,9 -tetrahydro-5H-benzocyclohepten-5-ones. Synthesis of 6-(2,2-Dichloroethylidene)-b,7,8,9-tetrahydro-5H-benzocyclohepten-5-one and of 5H-benzo[3,4]cyclohepta[2,l-b]pyran and 5H-Benzo[3,4]cyclo-hepta[1,2-e]-1,2-oxathiin derivatives

The 1,4-cycloaddition of dichloroketene to N,N-disubstituted 6-aminomethylene-b,7,8,9-tetra-hydro-5H-benzocyclohepten-5-ones afforded N,N-disubstituted 4-amino-3,3-dichloro-3,4,6,7-tetrahydro-5H-benzo[3,4]cyclohepta[2,l-b]pyran-2-ones only in the case of aromatic or strong hindering aliphatic N-substitution. The adducts gave N,N-disubstituted 4-amino-3-chloro-b,7-dihydro-5H-benzo[3,4]cyclohepta[2,l-b]pyran-2-ones by dehydrochlorination with collidine. Upon chromatography on neutral alumina, two products were instead isolated in the case of usual aliphatic N-substitution (diethylamine, piperidine), namely 6-(2,2-dichloroethylidene)-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one and the dehydrochlorinated 2-pyrone; this latter was the sole product in the case of pyrrolidine substitution. The 1,4-cycloaddition of sulfene occurred readily to give N,N-disubstituted 4-amino-3,4,6,7-tetrahydro-5H-benzo[3,4]cyclohepta-[1,2-e]-1,2-oxathiin 2,2-dioxidesin the case of both aliphatic and partially aromatic N-substitution.     

Biosynthetic Production of [N2,1,3,7,9-15N]Guanosine and [1,3,7,9-15N]inosine and conversion into [N6,1,3,7,9-15N]adenosine for structure elucidation of RNA by heteronuclear NMR

A procedure was developed for the biosynthetic preparation of ¹⁵N-labelled guanosine and inosine through the action of a mutant Bacillus subtilis strain. Crude [N²,1,3,7,9-¹⁵N]guanosine and [1,3,7,9-¹⁵N]inosine were isolated from the culture filtrate by precipitation and anion-exchange chromatography (Scheme 1). No cell lysis and no enzymatic degradation was necessary. The per-isobutyrylated derivatives 1 and 2 were isolated from a complex mixture, purified by virtue of their different lipophilicity, and separated in three steps involving normal-and reversed-phase silica-gel chromatography. One litre of complex nutrient medium yielded 8.44 mmol of guanosine derivative and 2.84 mmol of inosine derivative with high average ¹⁵N enrichment (83.5 and 91.9 atom-%, resp.). [N⁶,1,3,7,9-¹⁵N]Adenosine ( 4 ) was obtained from 2′,3′,5′-tri-O-isobutyryl[1,3,7,9-¹⁵N]inosine ( 1 ) through the ammonolysis of its 1,2,4-triazolyl derivative with aqueous ¹⁵NH₃ (Scheme 2).     

Reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene. ipso-Substitution of the tert-butyl group

The reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene follows the mechanism of ipso-substitution of the tert-butyl group that is in para-position relative to the endocyclic O atom of the heterocycle, predominantly yielding 8-(tert-butyl)-2,6-dichloro-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine (NMR data). The structure of its hydrolysis product, 8-(tert-butyl)-6-chloro-2-hydroxy-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine, was proved by X-ray diffraction analysis.     

Reaction of sulfene with heterocyclic N,N-disubstituted α-aminomethyleneketones. IX. Synthesis of 1,2-oxathiino[6,5-e]indole derivatives

The polar 1,4-cycloaddition of sulfene to N,N-disubstituted 5-aminomethylene-1,5,6,7-tetrahydro-1-methylindol-4-ones occurred only in the case of aliphatic N-substitution to give, generally in good yield, 4-dialkylamino-3,4,5,6-tetrahydro-7-methyl-7H-1,2-oxathiino[6,5-e]indole 2,2-dioxides IV. Full aromatization of IVa (4-NR₂ = dimethylamino) with DDQ in refluxing benzene gave in low yield 7-methyl-7H-1,2-oxathiino-[6,5-e]indole 2,2-dioxide, whereas the same reaction of IVe (4-NR₂ = morpholinyl) with excess DDQ afforded in low yield 7-methyl-4-morpholinyl-7H-1,2-oxathiino[6,5-e]indole 2,2-dioxide.     

1,3-bis(2,4,6-trinitrophenylaminooxy)propane and its 4-cyano-2,6-dinitrophenyl congener: Synthesis and properties

Starting from N-hydroxyphthalimide (5) and 1,3-dibromopropane (6) we obtained 1,3-bis(phthalimidooxy)propane (7) which led to 1,3-bis(aminooxy)propane dihydrochloride (8). From its reaction with picryl chloride or 4-cyano-2,6-dinitrochlorobenzene, the two title compounds (4b, 4a) were obtained. ¹H-NMR and ¹³C-NMR spectra are presented. For comparison with the analogous N-methoxy-2,6-dinitro-4-R-anilines 1a, 1b (R=CN or R=NO₂), wer report the hydrophobic characteristics (by RPTLC), electronic spectra for the neutral compounds and their anions, pK _a values, and the behavior towards oxidizers (DPPH, PbO₂, Pb(CH₃COO)₄, KMnO₄ and Ag₂O); DPPH converts compounds 1a, 1b and 4a, 4b into betainic structures 2a, 2b respectively.     

Regioselective ipso-nitration of calix[4]arenes

A novel protection/deprotection method leading to the regioselective ipso-substitution of calix[4]arenes is described. The introduction of nosyl (p-nitrobenzenesulfonyl) groups into the lower rim of partly alkylated tert-butylcalix[4]arenes leads subsequently to the exclusive ipso-nitration of the alkylated phenol rings, while the protecting groups can be easily removed in the next step. This method gives dialkoxy- or trialkoxy-substituted calix[4]arenes with nitro groups on the alkylated rings and tert-butyl groups on the remaining ones. The above substitution pattern is complementary to the isomers so far known in the chemistry of calix[4]arenes and could be used in the design of novel type of calixarene-based receptors.     

Anion receptors based on ureido-thiacalix[4]arenes

The regioselective ipso-nitration of tert-butylthiacalix[4]arene-tetrasulfone was used for the construction of thiacalixarene derivatives bearing one or two arylureido functions on the upper rim. The preorganization of ureido units using the thiacalix[4]arene moiety as a molecular scaffold leads to novel anion receptors with good complexation ability toward selected anions of various geometry (halides, carboxylates, HSO₄⁻, H₂PO₄⁻, NO₃⁻, CN⁻) in organic solvents.     

Radical Truce-Smiles reactions on an isoxazole template: Scope and limitations

The use of TiCl₃-HCl as promotor in the radical Truce-Smiles reactions of 2-(((3,5-dimethylisoxazol-4-yl)sulfonyl)oxy)benzenediazonium salts has been investigated in detail. During these reactions the desired Truce-Smiles rearrangement (via an ipso-substitution reaction) is accompanied by the formation of a number of by-products including dihydrobenzo[5,6][1,2]oxathiino[3,4-d]isoxazole 4,4-dioxides, dioxidobenzo[e][1,2]oxathiin-3-yl)ethan-1-ones, anilines and chloroaromatics. Replacing TiCl₃-HCl by Cu(NO₃)₂-Cu₂O as reductant in these reactions was found to afford broadly comparable product distributions. Competition and radical clock experiments also provide an indication of the relative susceptibility of the isoxazole nucleus towards attack by aryl radicals.     

Reaction of sulfene with heterocyclic N,N-disubstituted α-aminomethyleneketones. X. Synthesis of thieno[2,3-h]-1,2-benzoxathiin derivatives

The polar 1,4-cycloaddition of sulfene to N,N-disubstituted (E)5-aminomethylene-6,7-dihydrobenzo[b]-thiophen-4(5H)ones II gave in excellent yield and only in the case of aliphatic N-substitution, N,N-disubstituted 4-amino-3,4,5,6-tetrahydrothieno[2,3-h]-1,2-benzoxathiin 2,2-dioxides III, which are derivatives of the new heterocyclic system thieno[2,3-h]-1,2-benzoxathiin. Dehydrogenation with DDQ of cycloadducts IIIa-d was successful only in the case of IIIa (NR₂ = dimethylamino) to give in low yield 4-dimethylamino-3,4-dihydrothieno[2,3-h]-1,2-benzoxathiin 2,2-dioxide.     

Synthesis and Complexation of 1,2-Bis[(monoaza[15]crown-5)-N-yl]glyoxime. Crystal Structure of (1,2-Bis[(monoaza[15]crown-5)-N-yl]glyoximato)palladium(II)

A new vicinal dioxime ligand with two crown-ether groups, 1,2-bis[(monoaza[15]crown-5)-N-Yl]-glyoxime(LH₂), has been prepared from cyanogen di-N-oxide and monoaza[15]crown-5. Ni(II), Pd(II), and Pt(IV) complexes of LH₂ with or without alkali-metal ions bound to macrocyclic groups have been isolated. The high affinity of [Pd(LH)₂] and [Ni(LH)₂] for the K⁺ ion is observed in solvent extraction experiments. A single-crystal X-ray structure confirms the postulated geometry of [Pd(LH)₂]- The Pd-atom of the centro-symmetric molecule has square-planar PdN₄ coordination where Pd–N distances range from 1.978(3) to 1.970(3) Å. The N–Pd–N intraligand angle is 79.9(1)^°.     

Hg(II), Tl(III), Cu(I), and Pd(II) Complexes with 2,2'-Diphenyl-4,4'-Bithiazole (DPBTZ), Syntheses and X-Ray Crystal Structure of [Hg(DPBTZ)(SCN)2]

Reaction of the ligand 2,2′-diphenyl-4,4′-bithiazole (DPBTZ) with Hg(SCN)₂, Tl(NO₃)₃, CuCl, and PdCl₂ gives complexes with stoichiometry [Hg(DPBTZ)(SCN)₂], [Tl(DPBTZ)(NO₃)₃], [Cu(DPBTZ)(H₂O)Cl]_, and [Pd(DPBTZ)Cl₂]. The new complexes were characterized by elemental analyses and infrared spectroscopy. The crystal structure of [Hg(DPBTZ)(SCN)₂] determined by X-ray crystallography. The Hg atom in the title monomeric complex, (2,2′-diphenyl-4,4′-bithiazole)mercury(II)bisthiocyanate, [Hg(C₁₈H₁₂N₂S₂)(SCN)₂], is four-coordinate having an irregular tetrahedral geometry composed of two S atoms of thiocyanate ions [Hg-S 2.4025(15) and 2.4073(15) Å] and two N atoms of 2,2′-diphenyl-4,4′-bithiazole ligand [Hg-N 2.411(4) and 2.459(4) Å]. The bond angle S(3)-Hg(1)-S(4) of 147.46(5)° has the greatest derivation from ideal tetrahedral geometry. Intermolecular interaction between Hg(1) and two S atoms of two neighboring molecules, 3.9318(15) and 3.9640(18) Å, make the Hg(1) distort from a tetrahedron to a disordered octahedron. The attempts for preparation complexes of Tl(I), Pb(II), Bi(III), Cd(II) ions with 2,2′-diphenyl-4,4′-bithiazole ligand were not successful and also the attempts for preparation complexes of 4,4′,5,5′-tetraphenyl-2,2′-bithizole ligand with Cu(II), Ni(II), Co(II), Co(III), Mn(II), Mn(III), Fe(II), Fe(III), Cr(III), Zn(II), Tl(III), Pb(II), Hg(II), Cu(I), Pd(II) were not successful. This point can be regarded as the initial electron withdrawing of phenyl rings and also their spatial steric effects.     

Acid-Catalyzed [3,3]-Sigmatropic Rearrangements of N-Propargylanilines

The acid-catalyzed rearrangement of N-(1′,1′-dimethylprop-2′-ynyl)-, N-(1′-methylprop-2′-ynyl)-, and N-(1′-arylprop-2′-ynyl)-2,6-, 2,4,6-, 2,3,5,6-, and 2,3,4,5,6-substituted anilines in mixtures of 1N aqueous H₂SO₄ and ROH such as EtOH, PrOH, BuOH etc., or in CDCl₃ or CCl₄ in the presence of 4 to 9 mol-equiv. trifluoroacetic acid (TFA)has been investigated (cf. Scheme 12-25 and Tables 6 and 7). The rearrangement of N-(3′-X-1′,1′-dimethyl-prop-2′-ynyl)-2,6- and 2,4,6-trimethylanilines (X = Cl, Br, I) in CDCl₃/TFA occurs already at 20° with τ_1/2 of ca. 1 to 5 h to yield the corresponding 6-(1-X-3′-methylbuta-1,2′-dienyl)-2,6-dimethyl- or 2,4,6-trimethylcyclohexa-2,4-dien-1-iminium ions (cf. Scheme 13 and Footnotes 26 and 34) When the 4 position is not substituted, a consecutive [3,3]-sigmatropic rearrangement takes place to yield 2,6-dimethyl-4-(3′-X-1′,1′-dimethylprop-2′-ynyl)anilines (cf. Footnotes 26 and 34). A comparable behavior is exhibited by N-(3′-chloro-1′-phenylprop-2′-ynyl)-2,6-dimethylaniline ( 45 ., cf. Table 7). The acid-catalyzed rearrangement of the anilines with a Cl substituent at C(3′) in 1N aqueous H₂SO₄/ROH at 85-95°, in addition, leads to the formation of 7-chlorotricyclo[3.2.1.0^2,7]oct-3-en-8-ones as the result of an intramolecular Diels-Alder reaction of the primarily formed iminium ions followed by hydrolysis of the iminium function (or vice versa; cf. Schemes 13,23, and 25 as well as Table 7). When there is no X substituent at C(1′) of the iminium-ion intermediate, a [1,2]-sigmatropic shift of the allenyl moiety at C(6) occurs in competition to the [3,3]-sigmatropic rearrangement to yield the corresponding 3-allenyl-substituted anilines (cf. Schemes 12,14–18, and 20 as well as Tables 6 and 7). The rearrangement of (?)?(S)-N-(1′-phenylprop-2′-ynyl)-2,6-dimethylaniline ((?)- 38 ; cf. Table 7) in a mixture of 1N H₂SO₄/PrOH at 86° leads to the formation of (?)-(R)-3-(3′-phenylpropa-1′,2′-dienyl)-2,6-dimethylaniline ((?)- 91 ), (+)-(E)- and (?)-(Z)-6-benzylidene-1,5-dimethyltricyclo[3.2.1.0^2′7]oct-3-en-8-one ((+)-(E)- and (?)-(Z)- 92 , respectively), and (?)-(S)-2,6-dimethyl-4-( 1′-phenylprop-2′-ynyl)aniline((?)- 93 ). Recovered starting material (10%) showed a loss of 18% of its original optical purity. On the other hand, (+)-(E)- and (?)-(Z)- 92 showed the same optical purity as (minus;)- 38 , as expected for intramolecular concerted processes. The CD of (+)-(E)- and (?)-(Z)- 92 clearly showed that their tricyclic skeletons possess enantiomorphic structures (cf. Fig. 1). Similar results were obtained from the acid-catalyzed rearrangement of (?)-(S)-N-(3′-chloro-1′phenylprop-2′-ynyl)-2,6-dimethylaniline ((?)- 45 ; cf. Table 7). The recovered starting material exhibited in this case a loss of 48% of its original optical purity, showing that the Cl substituent favors the heterolytic cleavage of the N–C(1′) bond in (?)- 45. A still higher degree (78%) of loss of optical activity of the starting aniline was observed in the acid-catalyzed rearrangement of (?)-(S)-2,6-dimethyl-N-[1′-(p-tolyl)prop-2′-ynyl]aniline ((?)- 42 ; cf. Scheme 25). N-[1′-(p-anisyl)prop-2-ynyl]-2,4,6-trimethylaniline( 43 ; cf. Scheme 25) underwent no acid-catalyzed [3,3]-sigmatropic rearrangement at all. The acid-catalyzed rearrangement of N-(1′,1′-dimethylprop-2′-ynyl)aniline ( 25 ; cf. Scheme 10) in 1N H₂SO₄/BuOH at 100° led to no product formation due to the sensitivity of the expected product 53 against the reaction conditions. On the other hand, the acid-catalyzed rearrangement of the corresponding 3′-Cl derivative at 130° in aqueous H₂SO₄ in ethylene glycol led to the formation of 1,2,3,4-tetrahydro-2,2-dimethylquinolin-4-on ( 54 ; cf. Scheme 10), the hydrolysis product of the expected 4-chloro-1,2-dihydro-2,2-dimethylquinoline ( 56 ). Similarly, the acid-catalyzed rearrangement of N-(3′-bromo-1′-methylprop-2′-ynyl)-2,6-diisopropylaniline ( 37 ; cf. Scheme 21) yielded, by loss of one i-Pr group, 1,2,3,4-tetrahydro-8-isopropyl-2-methylquinolin-4-one ( 59 ).     

Dipolar Cycloaddition of Carbonyl Ylides Generated from Methyl cis-2-Diazoacetyl-1-cyclopropanecarboxylates

Carbonyl ylide generated from methyl cis-3-diazoacetyl-2,2-diphenyl-1-cyclopropanecarboxylate in the presence of Rh₂(OAc)₄ when brought into reaction of 1,3-dipolar cycloadditionя with N-arylmaleimides afforded substituted 4-aryl-7-methoxy-9,9-diphenyl-12-oxa-4-azatetracyclo-[5.4.1.0^2,6.0^8,10]dodecene-3,5,11-triones. Concurrent processes resulted in formation of cycloheptatrienes, hydroxyacetylcyclopropanecarboxylates, and benzophenone. Carbonyl ylide generated from methyl cis-2-diazoacetyl-1-cyclopropanecarboxylate in the same reaction gave rise to exo- and endo-4-aryl-7-methoxy-12-oxa-4-azatetracyclo[5.4.1.0^2,6 .0^8,10] dodecene-3,5,11-triones.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 2, 2005, pp. 205–213.Original Russian Text Copyright © 2005 by Molchanov, Diev, Kopf, Kostikov.     

THE SYNTHESIS OF 15N LABELED 6-NITRO-1,2,4-TRIAZOLO- [5,1-c][1,2,4]TRIAZIN-7-ONE

A general method for inclusion of the ¹⁵N label into the position 1 of 6-nitro-1,2,4-triazolo[5,1-c][1,2,4]triazin-7-one by using K¹⁵NO₃ has been developed.     

15N Studies of the Mechanisms of Nitration of Hexamethylenetetramine and 3,7-Diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane

Mechanistic studies of the nitration of hexamathylanetetramine (1) and some derivatives are reported and are compared with acetylation reactions. Nitration reactions, with nitric acid, were carried out using mixtures of [¹⁵N₄]- and [¹⁴N₄]-compounds and the destination of the nitrogen-isotopes in the products was determined mass spectrometrically. The results show that in nitration of (1) to give 3,7-dinitro-l,3,5,7-tetraazablcyclo[3.3.1]nonane (DPT) extensive ring cleavage occurs to give species containing single amino-nitrogen fragments. However the nitration of 3,7-diacetyl-1,3,5,7-tetraazabicyclo(3.3.1]nonane (DAPT) to 1,5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) involves selective cleavage of the methylene bridge. A synthesis of DADN by acetolysis of DPT is reported.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones VII. Synthesis of 2H,5H-[1]benzothiopyrano[4,3-b]pyran and 2H,5H-thiopyrano[4,3-b]pyran derivatives

The dipolar 1,4-cycloaddition of dichloroketerie to N,N-disubslituled 3-aminomethylene-2,3-dihydro-4-thiochromanones and 3-aminomethylenetelrahydro-4-thiopyranones gave N,N-disubstituted 4-amino-3,3-diehloro-3,4-dihydro-2H,5H-[1]benzolhiopyrano[4,3-b]pyran-2-ones and 4-amino-3,3-dichloro-3,4,7,8-tetrahydro-2H,5H-thiopyrano[4,3-b]pyran-2-ones, respectively, only in the ease of aromatic or strong hindering aliphatic N-substitution. The adducts gave N,N′-disubstituted 4-amino-3-chloro-2H,5H-[1]benzothiopyrano[4,3-b]pyran-2-ones and 4-amino-3-chloro-7,8-dihydro-2H,5H-thiopyrano[4,3-b]pyran-2-ones, respectively, by dehydro-chlorination with DBN. By chromatography on neutral alumina, 3-(2,2-dichloroethylidene)-2,3-dihydro-4-thiochromanone was isolated as an unstable liquid from the reaction between dichloroketerie and 3-diethylaminornethylene-2,3-dihydro-4-thiochromanone.     

Selective Upper-Rim Adamantylation of Calix[4]arenes

Lower-rim mono- and diacylated calix[4]arenes [acyl = C₆H₅CO, 3,5-(NO₂)₂C₆H₃CO] undergo selective adamantylation with 3-Y-1-adamantanols (Y = H, i-Pr, 4-MeC₆H₄) in trifluoroacetic acid at the free phenolic fragments of the macroring. The reaction provides a convenient preparative route to di-, tri-, and tetraadamantylated calix[4]arenes.     

2,6-Dithiodecahydro-1H,5H-Diimidazo[4,5,-b:4′,5′-e]Pyrazine and related dioxo- and diimino-decahydrodiimidazopyrazines

Thiourea condensed with 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine 2 in the presence of hydrochloric acid to give 2,6-dithiodecahydro-1 H,5H-diimidazo[4,5,-b:4′,5′-e]pyrazine 5 isolated as the dihydrochloride salt. The salt 5 . 2HCl was converted to the free base 5 by lithium hydroxide, to the dinitrate salt 5 . 2HNO₃ by silver nitrate, degraded to 2-thio-2,3,4,7-tetrahydro-1 H-imidazo[4,5-b]pyrazine 6 in a reaction with tert-butyl amine, and converted to 4,8-dihydro-4,8-dinitro-1H,5H-diimidazo[4,5-b:4′,5′-e]pyrazine-2,6- disulfonic acid 9 by nitric acid (100%) at −40°C. Denitration of the dinitramine 9 to give 4,8-dihydro-1H,5H-diimidazo[4,5-b:4′,5′-e]pyrazine 11 was brought about by methanolic hydrogen chloride in ether. In one run nitration without oxidation converted the salt 5 · 2HCl to the dinitrate salt of the 4,8-dinitro derivative 10 ; treatment with triethyl amine liberated the free base 10 from the salt. Degradation of 2,6-dioxo-1,3,4,5,7,8-hexanitrodecahydro-1H,5H-diimidazo[4,5-b:4′,5′-e]pyrazine 12 to 2-oxo-2,3-dihydro-1,3-dinitro-1H-imidazo[4,5-b] pyrazine 13 was brought about by hydrochloric acid. Treatment with lithium hydroxide also liberated 2,6-dioxodecahydro-1H,5H-diimidazo [4,5-b:4′,5′-e]pyrazine 3 from its dihydrochloride salt. Attempts to liberate 2,6-diiminodecahydro-1H, 5H-diimidazo[4,5-b:4′,5′-e]pyrazine 4 from its tetrahydrochloride salt led instead to intractable mixtures. The tetrahydrochloride salt 4 · 4HCl was converted to the dihydrochloride salt 4 · 2HCl in a reaction with tert-butyl amine.     

One-step synthesis of substituted 3,5-dinitropiperidines and 1,5-dinitro-3,7-diazabicyclo[3.3.1]nonanes from 1,3-dinitropropanes

1,5-Dinitro-3,7-diazabicyclo[3.3.1]nonane derivatives were synthesized in up to 83%yields by the Mannich reaction of 1,3-dinitropropanes with excess formaldehyde and primary amines. In some cases, for instance, when 2,2-dimethyl-1,3-dinitropropane and benzylamine or monoethanolamine are used, the reaction occurs with low yields or stops at the step of formation of 3,5-dinitropiperidines. The influence of the structure of the starting compounds and reaction conditions on the yields of 1,5-dinitro-3,7-diazabicyclo[3.3.1]nonanes and 3,5-dinitropiperidines was studied.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 405–411, February, 2005.