Unexpected formation of 6-methyl-4-(5-methylfuran-2-yl)-2-ethylsulfanylpyridine-3-carbonitrile from 2-methyl-4-(5-methylfuran-2-yl)-N-o-tolyl-5-cyano-6-ethylsulfanyl-1,4-dihydropyridine-3-carboxamide

Russian Journal of Organic Chemistry -     

Formation of oxopyridine ring from two cyanoacetanilide molecules via preliminary transformation of one of them into ethoxymethylidene derivative

Cyanoacetanilides reacted with their ethoxymethylidene derivatives to produce two regioisomeric products from the same linear intermediate, the isomer ratio depending on the substituents in the aromatic rings of the initial cyanoacetanilides.     

Naphthalene proton sponges as hydride donors: diverse appearances of the tert-amino-effect

It has been shown that the 1-NMe(2) group in the 2-substituted 1,8-bis(dimethylamino)naphthalenes (proton sponges) can intramolecularly donate a hydride ion to an appropriate electron-accepting ortho-substituent such as diarylcarbenium ion, β,β'-dicyanovinyl or methyleneiminium group. This produces the 1-N(+)(Me)=CH(2) functionality and triggers a number of further transformations (tert-amino effect) including peri-cyclization, ortho-cyclization or hydrolytic demethylation. In each particular case, the course of the reaction is determined by the nature of the ortho-substituent and the most potent nucleophile presenting in the reaction mixture. For 2,7-disubstituted 1,8-bis(dimethylamino)naphthalenes, two types of tandem tert-amino effect with the involvement of both peri-NMe(2) groups have been registered. The conclusion was made that proton sponges are generally more active in the tert-amino reactions than the corresponding monodimethylaminoarenes. This is ascribed both to higher electron donor ability of proton sponges and markedly shortened distance between electrophilic C(α)-atom in the ortho-substituent and hydrogen atoms of the nearest NMe(2) group. Most conversions observed proceed in good to high yields and are useful for the preparation of derivatives of benzo[h]quinoline, quino[7,8:7',8']quinoline, 2,3-dihydroperimidine, N,N,N'-trimethyl-1,8-diaminonaphthalene and proton sponge itself.     

One-Pot Synthesis of Thieno[2,3-b]pyridine and Pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine Derivatives

Russian Journal of Organic Chemistry - 2-Acyl-4,5,6-trialkyl-3-aminothieno[2,3-b]pyridines,...     

Synthesis, molecular and crystal structure of 2-[2-(2-amino-3-cyano-4H-chromen-4-yl)-cyclohexylidene]malononitrile

Condensation of salicylaldehyde with cyclohexylidenemalononitrile and hydrazine hydrate results in 2-[2-(2-amino-3-cyano-4H-chromen-4-yl)cyclohexylidene]malononitrile, the structure of which was studied by XRD.     

Experimental determination and interpretation of fluorescence and fluorescence excitation spectra of 1,2-benzanthracene cooled in supersonic jet

We measured the fluorescence and fluorescence excitation spectra of supersonic jet-cooled 1,2-benzanthracene. Using the MO/M8ST method, we calculated the frequencies of in-plane vibrations in the ground and first excited singlet electronic states, and, in the Franck-Condon approximation, we calculated the intensities of transitions between them. Experimental spectra are interpreted based on these data. In the fluorescence excitation spectrum, the position of the line of the 0–0 transition (26535 ± 1 cm⁻¹), which is the most intense, is determined.     

Decay of the monochromatic capillary wave

It was demonstrated by direct numerical simulation that, in the case of weakly nonlinear capillary waves, one can get resonant waves interaction on the discrete grid when resonant conditions are never fulfilled exactly. The waves’s decay pattern was obtained. The influence of the mismatch of resonant condition was studied as well.     

Synthesis and crystal structure of 7-allylseleno-5-amino-8-cyano-3-ethoxycarbonyl-4-(2-furyl)-1,4-dihydro-2-methyi-1,6-naphthyridine

The reaction of 2-furylmethylideneacetoacetic ester with cyanoselenoacetamide afforded 7-allylseleno-5-amino-S-cyano-3-ethoxycarbonyl-4-(2-furyl)-1,4-dihydro-2-methyl-1,6naphthyridine, the structure of which has been established by X-ray structural study.Translated fromlzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 437–440, February, 1996.     

Rearrangement of 2-amino-1-aryl-1,4-dihydropyridines

Heating of 2-amino-1-aryl-1,4-dihydropyridines in acidic aqueous media gives 2-arylamino-1,4-dihydropyridines. The reaction formally involves the migration of the aryl substituent from the endo-to exocyclic N atom. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1259–1260, July, 2006.