4,5-Bis(dimethylamino)quinolines: Proton Sponge versus Azine Behavior

Two first representatives, 5 and 6, of the still unknown 4,5-bis(dimethylamino)quinoline have been synthesized and studied. While the former, being protonated either at the peri-NMe(2) groups or at the ring nitrogen, has been shown to display properties of both a proton sponge and azine, its counterpart 6 behaves exclusively as azine giving only a quinolinium salt.     

1,2-Bis(dimethylamino)-3,4,5-triphenyl-3,4,5-triphospha-1,2-diborolan und 1,2-Bis(dimethylamino)-3,4,5,6-tetra-tbutyl-3,4,5,6-tetraphospha-1,2-diborin: Synthese und Struktur sowie Berechnungen zur Molekülstruktur

1,2-Bis(dimethylamino)-3,4,5-triphenyl-3,4,5-triphospha-1,2-diborolane and 1,2-Bis(dimethylamino)-3,4,5,6-tetra-tbutyl-3,4,5,6-tetraphospha-1,2-diborine: Synthesis and Structure as well as Calculations on the Molecular Structure The diphosphides K₂[(C₆H₅)P? (C₆H₅)P? P(C₆H₅)], 4 or K₂[(tBuP)? (tBuP)₂? P(tBu)], 5 , react with (ClBNMe₂)₂ to form the binary 5-membered ring system 1,2-bis(dimethylamino)-3,4,5-triphenyl-3,4,5-triphospha-1,2-diborolane (C₆H₅P)₃(BNMe₂)₂, 2a , and the 6-membered ring system 1,2-bis(dimethylamino)-3,4,5,6-tetra-tbutyl-3,4,5,6-tetraphospha-1,2-diborine, (tBuP)₄(BNMe₂)₂, 3a , respectively. 2a and 3a could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analyses. The two ring systems are folded; 2a exists in the ?envelope”?- 3a in the ?boat”?-conformation. Ab initio computations for 3,4,5-triphospha-1,2-diborolane M5 show that the global minimum is characterized by one B? P double bond. The parent compound geometry M6 is characterized by transannular bonding in the PH? BH? BH? PH moiety which differs in character from those in the four- and five-membered rings (BH)₂(PH)₂ and (BH)₂(PH)₃ M5 d , respectively. Explicit calculation of the influence of amino substituents on boron improved agreement of the bond length between computed and X-ray data.     

4,5-Bis(chloromethyl)uracil

A one-step synthesis of 4,5-bis(chloromethyl)uracil from readily available starting materials has been accomplished. This substance is a stable, crystalline solid which undergoes facile nucleophilic attack to produce various di-substituted uracil derivatives.     

3,6-Bis(dimethylamino)-10-propylacridinium iodide

In the title compound, C₂₀H₂₆N₃⁺·I⁻, the acridinium moiety shows mirror symmetry about the central C—N vector. The fused tricyclic system is only approximately planar and the geometry is affected by the presence of both di­methyl­amino groups and the propyl substitution at the central N atom. The propyl chain adopts an extended trans conformation and the plane through the chain C atoms is perpendicular to the mean plane through the rings. The I⁻ ion is involved in short-range hydrogen-bonding interactions with two centrosymmetrically related cations via three activated acridinium C atoms. Stacks of acridinium cations propagate through the crystal along the c direction. The ring overlap is partial, but the di­methyl­amino groups also participate in the stacking.     

Acyl- und Alkylidenphosphane. XIX. Molekül- und Kristallstruktur des 2,4-Bis(dimethylamino)-1,3-diphenyl-1,3-diphosphetans

Acyl and Alkylidenephosphines. XlX. Molecular and Crystal Structure of 2,4-Bis (dimethyl-amino) ?1,3-diphenyl-l, 3-diphosphetane 2,4-Bis(dimethylamino)-1,3-diphenyl-1,3-diphosphetane 2a which is isolated as a byproduct in the synthesis of (E)-(dimethylamino)methylidene-phenylphosphine 1a crystallizes in the monoclinic space group P2₁/c. The dimensions of the unit cell determined at ?65 ± 5°C are: a = 1 004(1); b = 1 018(3); c = 1 873(2) pm; β = 105.15(8)°; Z = 4. As it is shown by a low temperature X-ray structure determination (R_g = 3.5%) the phenyl groups are placed above and the dimethylamino groups below the folded 1,3-diphosphetane ring; the molecule with its differently twisted substituents, however, deviates considerably from point symmetry mm2. The dihedral angle between the P1? C1n? P2 planes (n = 1 or 2) is found to be 153°. The relatively long Pn? C1n bond distances (187 to 191 pm) indicate a strained ring system; in solution 2a decomposes to some extent and forms monomeric 1a again. Further characteristic average bond distances and angles are: Pn? C4n (phenyl) 184; C? N 146 pm; P1? C1n? P2 93°; C11? Pn? C12 84° and Pn? C1n? Nn 116°.     

peri-Naphthylenediamines 18. 1,8-Bis(dimethylamino)-4-vinylnaphthalene

The 1-[1,8-bis(dimethylamino)-4-naphthyl[ethyl carbocation generated from the corresponding alcohol in benzene in the presence of Al₂O₃ undergoes elimination according to theE1 mechanism to give previously unknown 1,8-bis(dimethylami no)-4-vinyl naphthalene in a good yield. This compound was also synthesized from 1,8-bis(dimethylamino)-4-formylnaphthalene by the Wittig reaction. Polymerization of the vinylic derivative obtained was studied.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2297–2300, September, 1996.