Condensation of O-phenylhydroxylamine with some unsymmetrical heterocyclic ketones

2-Methyl-1,2,3,4-tetrahydrobenzofuro[2,3-c]pyridine, 3,4-dihydro-1H-thiopyrano[3,4-b]benzofuran, 2,3-dihydro-4H-thiopyrano[3,2-b]benzofuran 1,1-dioxide, and 1,3,4,5-tetrahydrothiepino[4,3-b]benzofuran 2,2-dioxide, respectively, were synthesized by condensation of O-phenylhydroxylamine with N-methyl-3-piperidone, tetrahydro-3-thiopyrone, tetrahydro-3-thiopyrone S,S-dioxide, and 4-thiepanone S,S-dioxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 315–318, March, 1973.     

Reaction of ketones with lithium hexamethyldisilazide: competitive enolizations and 1,2-additions

Reaction of 2-methylcyclohexanone with lithium hexamethyldisilazide (LiHMDS, TMS(2)NLi) displays highly solvent-dependent chemoselectivity. LiHMDS in THF/toluene effect enolization. Rate studies using in situ IR spectroscopy are consistent with a THF concentration-dependent monomer-based pathway. LiHMDS in pyrrolidine/toluene affords exclusively 1,2-addition of the pyrrolidine fragment to form an alpha-amino alkoxide-LiHMDS mixed dimer shown to be a pair of conformers by using (6)Li, (15)N, and (13)C NMR spectroscopies. Rate studies are consistent with a monomer-based transition structure [(TMS(2)NLi)(ketone)(pyrrolidine)(3)](). The partitioning between enolization and 1,2-addition is kinetically controlled.     

Reaction of halogens with some α,β-unsaturated aldehydes and ketones

Mechanisms are proposed to account for evidence indicating that some simple α,β-unsaturated aldehydes and ketones do not react with halogens by the expected attack on the CC bond.     

Acetylenic ketones. Part V. Reaction of acetylenic ketones with thiourea and some of its derivatives

Aroylphenylacetylenes (I) reacted with thiourea and S-benzylisothiourea to give 4,6-diaryl-pyrimidine-2(1H)thiones (IV) and α-aroyl-β-benzylmercaptostyrenes (X), respectively. Methyla-tion and acetylation of the thiones (IV) gave the corresponding S-methyl- (V) and S-acetyl- (VI) derivatives, respectively. The oxidation of these thiones gave the corresponding disulfide derivatives (VII). Reaction of α-aroyl-β-benzylmercaptostyrenes (X) with hydrazine hydrate and phenylhydrazine gave 3(5)-aryl-5(3)-phenylpyrazoles (XI) and 3-aryl-1,5-diphenylpyrazoles (XIII), respectively. Reaction of aroylphenylacetylenes (1) with N-allylthiourea gave 1-allyl-4,6-diaryl-pyrimidine-2-thiones (XVI).     

Synthesis of heterocyclic phthalimidoalkyl ketones

We have investigated the 1,3-dipolar cycloaddition of dehydrobenzene, N-phenyl-maleimide, and diethyl acetylenedicarboxylate to phthalimidoalkyl diazomethyl ketones, and have obtained phthalimide derivatives of amino ketones of the indazole, pyrazole, and pyrrolo[3,4-d]-2-pyrazoline series.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 78–81, January, 1984.     

Reaction of difluoronitroacetyl fluoride with ketones

Conclusions A method was developed for the preparation of -diketones that contain the CF₂NO₂ grouping.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2350–2351, October, 1973.     

Reaction of perfluoro ketones with hexamethyldisilazane

Conclusions Perfluoro ketones react with hexamethyldisilazane under mild conditions to give 2-trimethylsilyloxy-2-trtmethylsilylaminoperfluoropropanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2352–2353, October, 1972.     

Reaction of ethynyl ketones with o-phenylenediamine

2,4-Diaryl-3H-benzo-1,5-diazepines were obtained by reaction of ethynyl ketones with o-phenylenediamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1421–1422, October, 1973.     

Reaction of cyclic ketones with KOH-DMSO

Upon reaction of cycloalkanones with a KOH-DMSO system 2-methylenecycloal-kanols are formed, the yield (10–37%) of which decreases in the series: cyclohexanone > cycloheptanone > cyclooctanone > cyclododecanone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1601–1605, July, 1990.     

Reaction of acetylferrocene with dimethylformamide dimethyl acetal and some transformations of the reaction product

1-Dimethylamino-3-ferrocenyl-3-oxoprop-1-ene was synthesized by the reaction of acetylferrocene with dimethylformamide dimethyl acetal. Its reactivity in the reactions with mononucleophilic (sodium salts of phenol, thiophenol, benzenesulfinate, diethylphosphorous acid) and binucleophilic reagents (hydrazine hydrate, hydroxylamine, amidines, 1,2-diaminobenzene, 2-aminophenol, 2-aminothiophenol) and methyl iodide was studied. As a result, we obtained new ferrocene-containing α-keto-unsaturated compounds and heterocycles of pyrazole, isoxazole, pyrimidine, and benzazepine series. In the reaction with CH₃I formed ferrocenoylacetylene which in the presence of dicarbonyl-bis(triphenylphosphine)nickel catalyst easily trimerized to give a mixture of 1,2,4- and 1,3,5-triferrocenoylbenzene.     

Novel reduction of perfluoroalkyl ketones with lithium alkoxides

The reaction of tert-butyl N-(2-bromophenyl)carbamate (1) with ethyl perfluorooctanoate in the presence of tert-butyllithium did not give the desired N-(2-perfluorooctanoylphenyl)carbamate (3) but gave 1-hydroxy-1H-perfluorooctyl compound (4), which was supposed to be formed by the reduction of 3. A similar reaction of 2,2,2-trifluoroacetophenone with tert-butyllithium did not gave any reduction product. Detailed investigation showed that lithium ethoxide worked as the reducing agent of this abnormal reduction. By the reaction of lithium isopropoxide, an aldol product from 2,2,2-trifluoroacetophenone with acetone was isolated, while perfluoroheptyl or perfluoropropyl phenyl ketones were reduced by this alkoxide in a high yield without formation of the aldol adduct.     

Adsorptive stripping voltammetric behaviour of copper complexes of some heterocyclic azo compounds

Controlled adsorptive accumulation of copper complexed with TAN, TAC, TAR and TAM (heterocyclic azo-compounds) on a static mercury drop electrode provides the basis for the direct stripping measurement of this element in the nanomolar concentration level. The ligand TAN exhibited great sensitivity and better separation of the peak current of the ligand in relation to the complex. The reduction current of adsorbed complex ions of copper is measured by linear scan cathodic stripping voltammetry, preceded by a period of accumulation of a few minutes. The peak potential is at approximately -0.37 V vs. Ag/AgCl. Optimal experimental parameters were found to be a TAN concentration of 1 x 10(-5)M, an accumulation potential of -0.22 V, and a solution pH of 3.7 (acetate buffer). The detection limit is 0.8nM after a 5-min accumulation with a stirred solution, and the response is linear up to 50 mug/l. Many common cations and anions do not interfere in the determination of copper. The interference of titanium is eliminated by addition of fluoride ion. Results are reported for a fresh water sample.     

Conformational study of chiral heterocyclic enamino ketones

An assumption regarding the existence of a homoconjugation effect involving enaminoketo and phenyl groups as a result of the drawing together in space of their orbitals was made on the basis of circular dichroism (CD) data and an examination of the preferred conformations of two-ring enamino ketones with -phenylethyl and -benzylethyl substituents. A study of enamino ketones with a chiral alkyl substituent attached to the nitrogen atom made it possible to confirm this assumption.Communication XLIX from the series Stereochemical Studies. See [1] for communication XLVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1230–1233, September, 1978.