A novel pyrrole synthesis

The silver(I)-promoted oxidative cyclization of homopropargylamines at room temperature provides a novel access to pyrroles. Homopropargylamines are readily available by the addition of a propargyl Grignard reagent to Schiff bases.     

A novel synthesis of perfluoroalkylglycine

Perfluoroalkylglycine was obtained through perfluoroalkylation of 2-phenyl-5-etho-xyoxazole using RFI-Na2S2O4 reagent system, followed by acid hydrolysis of the intermediates, 2-phenyl-4-perfluoroalkyl-5-ethoxyoxazole and 2-phenyl-4-perfluoroalkyl-2-oxazolin-5-one.     

A novel synthesis of tetramesityldisilene

Dimesityldiclorosilane undergoes reductive coupling with potassium-graphite to afford a mixture of cyclic polysilanes in a high yield and purity; this mixture is quantitatively converted to the title compound by photochemical irradiation.     

A novel synthesis of pyrromethenones

Pyrromethenones are prepared by a process involving acylation of an N-aminopyrrole with a suitable acetylenic acid,followed by sequential 5-exo-dig cyclization and 3,5-sigmatropic shift.     

A novel synthesis of Aporhoeadanes

A one-pot synthesis of aporhoeadanes from the reaction of 3,4-dihydro-isoquinolines, 2-chloromethylbenzoyl chloride and sodium hydroxide, is described.     

A novel three-component butenolide synthesis

[reaction: see text]. 5-Acylamino butenolides can be assembled by a multicomponent reaction (MCR) of isocyanides, glyoxals, and acetophosphonic acid diethylesters, followed by a intramolecular Wittig-type reaction. The reaction can be performed either in one pot or with the isolation of the intermediate Passerini product. This versatile reaction offers three independent inputs displayed in the final product. Applications in combinatorial chemistry and natural product synthesis can be envisioned.     

A novel synthesis of 3H-pyrroles

Reaction of isopropylphenyl- and isopropyl-2-thienylketoximes with acetylene, catalyzed by the system MOH (M=Na, K)-DMSO, gave 2-phenyl- and 2-(2-thienyl)-3,3-dimethyl-3H-pyrroles as well as the reaction intermediates O-vinylisopropylphenylketoxime and 2-phenyl-3,3-dimethyl-5-hydroxypyrroline. The yield of the condensation products depends on the structure of the ketoximes and the conditions for the reaction with acetylene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1371–1374, October, 1991.     

A novel synthesis of 5-acylaminooxazoles

1,2-Diacylamino-1,2-di(benzotriazol-1-yl)ethanes 2 , easily prepared from the condensation of 1,2-di(benzotriazol-1-yl)ethane-1,2-diol (1) and primary amides, were converted to 5-acylaminooxazoles in good to moderate yields via intramolecular cyclization upon treatment with sodium hydride.     

A novel synthesis of 9-hydroxyaporphine

(±)-N-Methyllaurotetanine (3) was readily prepared $\text{via}$ the $\text{o}$-quinol acetate (2), which was obtained from the 1-(3′-hydroxybenzyl)-tetrahydroisoquinoline (1) by lead tetraacetate oxidation.     

A novel synthesis of functionalized allylsilanes

A novel facile synthesis of substituted and functionalized allylsilane has been developed. This essentially one-pot procedure involves (1) (dimethylphenylsilyl)methyl cerium chloride addition to cyclopropyl ketone and (2) MgI(2) etherate-mediated Julia homoallylic transposition of the corresponding cyclopropyl carbinol. The bifunctional homoiodo allylsilanes, readily accessible by this method, would be useful and versatile synthons in organic synthesis. [reaction: see text]     

A novel synthesis of quinone-immonium dyes

A new method was invoked to synthesize the colored quinoneimmonium cations from the reactions of DMSO with aromatic amines. The novel feature about this method is the use of DMSO as the methylating agent with a lewis acid such as TiCl₄ as a catalyst. This reduced the number of steps traditionally used to prepare these dyes from aromatic amines.     

A novel synthesis of 2,3-diaminophenazine

The title heterocyclic 2,3-diaminophenazine (DAP) hydrochloride with the crystallization solvent were obtained from three different routes and their structures were determined by X-ray diffraction, elemental analysis, and IR.     

A novel synthesis of 2,5-diphenylpyrazine

The compound C₁₆H₁₂N₂ (2,5-diphenylpyrazine) was obtained as the by-product of synthesizing 5H-Imidazol[2,3-b]isoquinoline-1-ethanol-5-one,1,2,3,10b-tetrahydro-, β(S)-phenyl-3(S)-phenyl-(compound 2), and its structure was determined by X-ray diffraction. The crystal is monoclinic, P2(1)/c, a = 13.466(5) Å, α = 90.00º, b = 5.758(2) Å, β = 93.049(9)º, c = 7.713(3) Å, γ = 90.00º, V = 597.2(4) Å³, Z = 2, Dcalc. = 1.292 mg/m³; the final R factor is R₁ = 0.0592, 771 for reflections with I ₀ > 2σ(I ₀).     

A novel convenient synthesis of benzoquinazolines

[reaction: see text] A novel synthetic pathway to benzoquinazolines from naphthylamines is reported. Benzoquinazoline nucleus was cyclized in good yield from N-protected naphthylamines using hexamethylenetetramine in TFA and potassium ferricyanide in aqueous ethanolic KOH. This method is efficient and convenient with respect to previously reported synthetic pathways.