Showing papers on "Boron tribromide published in 1989"

Synthesis and photocytotoxicity of some new substituted phthalocyanines.

Abstract: Some new, ring-substituted phthalocyanines have been synthesized and underwent preliminary testing for photodynamic activity using the colony forming ability of Chinese hamster cells in culture as an endpoint. Using 4-(3-N,N-diethylaminopropyl)phthalonitrile as a precursor, the previously unknown metal-free 2,9,16,23-tetra-(3-N,N-diethylaminopropyl)phthalocyanine was prepared and converted to its zinc (II) and its cationic water-soluble 2,9,16,23-tetramethylammonium zinc (II) iodide derivatives. Other new phthalocyanine derivatives tested, include a 2,9,16,23-tetra(2-hydroxymethyl-2-methylbutoxy)phthalocyaninato zinc (II) and 2,3,9,10,16,17,23,24-octahydroxyphthalocyaninato zinc (II) derivatives. Boron tribromide cleavage of the newly prepared and fully characterized 2,3,9,10,16,17,23,24-octamethoxyphthalocyanine gave the unstable metal-free octahydroxyphthalocyanine, which could only be characterized by ultraviolet-visible, NMR and IR spectroscopy.

Synthesis of Apogalanthamine Analogues as α-Adrenergic Blocking Agents. XIII. Syntheses of Phenolic 8-Hydroxy-5, 6, 7, 8-tetrahydrodibenz[c, e]azocines

Abstract: 10, 11-Diphenolic 8-hydroxy-5, 6, 7, 8-tetrahydrodibenz[c, e]azocine 3, having a partial structure of adrenaline, was prepared by demethylation of the dimethoxyazocine 12 with boron tribromide. The related monophenolic 8-hydroxyazocines 4 and 5 were prepared by cyclization of the dihalogeno-β-phenylethanolamines 6c and 7c with zerovalent nickel, followed by hydrolysis and debenzylation of the O-protected dibenz[c, e]azocines 13 and 14, respectively.

Mixtures of reactive thermosetting resins which are stable at ambient temperature, latent catalyst complexes for hardening said mixtures, processes for their manufacture, and heat-hardened resins obtained from said mixtures

Abstract: Mixtures of reactive thermosetting resins which are stable at ambient temperature, latent catalyst complexes for hardening said mixtures, processes for their manufacture, and heat-hardened resins obtained from said mixtures. Mixtures of heat-reactive thermosetting resins which are stable at ambient temperature for use in impregnating insulation for electrical materials or in the preparation of molding products or composite materials, comprising liquid oligo- or poly-isocyanate compounds and liquid epoxy resins and a latent hardening catalyst which is inert at ambient temperature and is composed of an addition complex of an amine compound from the group consisting of the amines, the alkylhydrazines and the imidazoles, and a boron halide. They additionally comprise a small quantity of maleic anhydride or the boron halide is boron tribromide with no addition of maleic anhydride. Latent catalyst complexes of these mixtures, formed by the addition complexes of BBr 3 and an amine, an alkylhydrazine or an imidazole. Their manufacturing processes and the resins obtained from said mixtures.

Room temperature-stable blends of heat-curable reactive resins, latent catalyst complexes for these blends, process for their manufacture and the heat-curable resins obtained from these blends

Abstract: Mixtures, which are stable at ambient temperature, of hot- thermosetting reactive resins for insulating impregnation of electrical materials or for the preparation of moulded materials or of composite materials, which mixtures comprise liquid oligoisocyanate or polyisocyanate compounds and liquid epoxide resins and a latent hardening catalyst which is inactive at ambient temperature and which consists of an addition complex of an amine compound from the group consisting of the amines, the alkylhydrazines and the imidazoles, with a boron halide. The mixtures furthermore comprise a small quantity of maleic anhydride, or the boron halide is boron tribromide, without addition of maleic anhydride. Latent catalyst complexes for these mixtures, formed by the addition complexes of BBr3 and an amine, an alkylhydrazine or an imidazole, their processes of preparation, and the resins obtained from these mixtures. … … (days)

Indole derivatives. 135. 5-[2-(4-Methoxyphenyl)ethenyl]indolines and indoles

Abstract: 5-[2-(4-Methoxyphenyl)ethenyl]indolines were obtained from 5-formyl-1-methyl- or 5-forrayl-1-benzylindolines by the Witting reaction with 4-methoxybenzylidenetriphenylphosphorane. Their dehydrogenation led to the formation of the corresponding compounds of the indole series. The corresponding hydroxy compounds were obtained by demethylation of the methoxyindole with boron tribromide and were converted into the acetoxy derivatives of indoline and indole.

Synthesis of carbon‐14 and tritium labeled dopamine beta‐hydroxylase inhibitors of the imidazolinethione type

Abstract: 1-[(3,5-Difluoro-4-hydroxyphenyl)methyl]-1,3-dihydro-2H-imidazole-2-thione, 1-[(3,5-difluoro-4-methoxyphenyl)methyl]-1,3-dihydro-2H-imidazole-2-thione, and 1-[(3,5-difluorophenyl)methyl]-1,3-dihydro-2H-imidazole-2-thione (SK&F 102048, SK&F 102055 and SK&F 102698, respectively) were synthesized in carbon-14 and tritium labeled forms. Carbon-14 from potassium [14 C]thiocyanate was incorporated into the imidazolethione ring of SK&F 102055 and SK&F 102698 at C-2 by condensation with N-(2,2-dimethoxyethyl)-3,5-difluoro-4-methoxybenzenemethanamine or N-(2,2-dimeth-oxyethyl)-3,5-difluorobenzenemethanamine. Treatment of SK&F [2-14 C] 102055 with boron tribromide gave SK&F [2-14 C] 102048. Tritiated SK&F 102048 was synthesized by sodium [3H]borohydride reduction of N-(3,5-difluoro-4-methoxyphenylmethylene)-2,2-dimethoxy-ethanamine, followed by condensation with potassium thiocyanate and demethylation with boron tribromide.

2-(1-Alkenyl)- and 2-Aryl-Substituted Four-Membered Cyclic Nitrones as Precursors for 2,3,4-Substituted Pyridines and Quinolines.

Abstract: Reaction of the 2-(1-alkenyl)-substituted four-membered cyclic nitrones 3 with KOtBu gave the corresponding α,β-γ,δ-unsaturated oximes 6 which were converted into the substituted pyridines 9 , either by azeotropic removal of water in refluxing benzene or by reactfon in a 1:1 mixture of acetic anhydride and acetic acid at room temperature. Treatment of pyridine 9c with boron tribromide afforded the benzopyrano[4,3-c]pyridine derivatte 10. Reaction of the 2-aryl-substituted four-membered cyclic nitrones 4 with acetyl chloride yielded the 0 -acetylated oximes 12 which cyclized upon irradiation to the 2,3,4-substituted quinolines 14.