Syntheses proceeding from <Emphasis Type=Italic>N</Emphasis>-(oxiran-2-ylmethyl)-<Emphasis Type=Italic>N</Emphasis>-ethylaniline

The preparation of N-(oxiran-2-ylmethyl)-N-ethylaniline was developed. The compound was used in the synthesis of new N-derivatives of aromatic amines containing vicinal aminoalcohol moieties.     

Synthesis and some transformations of <Emphasis Type=Italic>N</Emphasis>,2,2-trimethyltetrahydro-2<Emphasis Type=Italic>H</Emphasis>-pyran-4-amine

Reaction of 2,2-dimethyltetrahydro-2H-pyran-4-one with aqueous methanamine, followed by reduction of the Schiff base thus obtained with sodium tetrahydridoborate gave N,2,2-trimethyltetrahydro-2H-pyran-4-amine which was subjected to cyanoethylation with acrylonitrile. The resulting 3-(2,2-dimethyltetrahydro-2H-pyran-4-ylmethylamino)propanenitrile was reduced with lithium tetrahydridoaluminate to N-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-N-methylpropane-1,3-diamine, and some chemical transformations of the latter were studied.     

Regioselective <Emphasis Type=Italic>N</Emphasis>-alkylation of (2-chloroquinolin-3-yl) methanol with <Emphasis Type=Italic>N</Emphasis>-heterocyclic compounds using the Mitsunobu reagent

The Mitsunobu reaction is a well-established fundamental reaction and has been widely applied in organic synthesis. In this paper, under Mitsunobu conditions dehydration proceeds between (2-chloroquinolin-3-yl)methanol and nitrogen heterocyclic compounds such as quinazolinone, pyrimidone, 2-oxoquinoline in dry THF in the presence of triethylamine, triphenylphosphane and diethyl azodicarboxylate to give the corresponding products. As part of our recent research, we attempted to couple two N-heterocyclic compounds under Mitsunobu reaction conditions to provide efficient building blocks for natural product synthesis.     

The zwitterion of <Emphasis Type=Italic>N</Emphasis>-(2-carboxyphenyl)-4-dimethylaminebenzylideneimine

The crystal and molecular structures of N-(2-carboxyphenyl)-4-dimethylaminebenzylideneimine and its protonated form have been determined. The Schiff base exists as the zwitterion, which is stabilized by the intramolecular ionic hydrogen bond. According to quantum-mechanical calculation results this tautomeric form is energetically unfavorable but in the solid and liquid state the intermolecular interactions support zwitterionic form.     

Copolymers of <Emphasis Type="Italic">N</Emphasis>-vinyl-2-pyrrolidone and condensation polymers

The results of study on the radical polymerization of N-vinyl-2-pyrrolidone containing a dissolved polyimide, an aromatic polyamide, and a polyarylate are presented. Formation of both poly(vinylpyrrolidone) homopolymer and its copolymers with the above condensation polymers is detected. The obtained (co)polymers differ from poly(vinylpyrrolidone) in heat resistance and solubility. It was shown that polyimides can be prepared in a N-vinyl-2-pyrrolidone medium followed by in situ polymerization of the latter.     

Ultrasound-accelerated one-pot synthesis of <Emphasis Type=Italic>N</Emphasis>-acetyl-2-aryl-1,2-dihydro-4<Emphasis Type=Italic>H</Emphasis>-3,1-benzoxazin-4-ones

The one-pot synthesis of N-acetyl-2-aryl-1,2-dihydro-4H-3,1-benzoxazin-4-one derivatives from the condensation reaction of anthranilic acids with heteroaromatic aldehydes in the presence of excess amount of acetic anhydride has been explored. The reactions proceed smoothly under ultrasound irradiation and without catalyst at 35 − 40 °C to afford the title products in high yields.     

Oxidative cyclization of <Emphasis Type=Italic>N</Emphasis>-alkyl-2-arylhydrazonothioacetamides

Oxidative cyclization of N-alkyl-2-arylhydrazono-2-cyanothioacetamides by the action of N-chlorosuccinimide, bromine, or iodine affords 4-cyano-5-imino-1,2,3-thiadiazoles.     

Formation of pyrrolinium derivatives in the bromination reaction of <Emphasis Type=Italic>N</Emphasis>,<Emphasis Type=Italic>N</Emphasis>-dipropargyl ammonium salts

Bromination of ammonium salts containing two propargyl groups afforded bromine-substituted derivatives of pyrrolinium salts. The reactions of piperidinium and morpholinium analogs resulted in spirocyclic ammonium salts.     

Synthesis and structure of <Emphasis Type=Italic>N</Emphasis>-(2-silatranylethyl)pyrazoles

Organosilicon pyrazole derivatives containing a 2-siltranylethyl fragment on the nitrogen atom were synthesized, and their structural and stereoelectronic parameters were determined by X-ray analysis and ¹H, ¹³C, and ²⁹Si NMR spectroscopy. The nature of interaction between the pyrazole and silatrane fragments was studied.     

Synthesis of 3-acetyl-6-(<Emphasis Type=Italic>o</Emphasis>-methyl benzoyl)-<Emphasis Type=Italic>N</Emphasis>-ethylcarbazole

3-Acetyl-6-(o-methyl benzoyl)-N-ethylcarbazole was prepared through successive o-methyl benzoylation and acetylation of N-ethylcarbazole in one pot. The overall yield was 85.6% and the structure was confirmed by ¹H-NMR and ¹³C-NMR. A preliminary investigation had also been carried out on the mechanism of the o-methyl benzoylation of N-ethylcarbazole.     

Synthesis and properties of symmetrical <Emphasis Type=Italic>N</Emphasis>,<Emphasis Type=Italic>N</Emphasis>'-Bis(R-adamantan-1-yl)ureas as target-oriented soluble epoxide hydrolase (sEH) inhibitors

Self-condensation of substituted adamantan-1-yl isocyanates in THF in the presence of DBU afforded 91–96% of symmetrical ureas as target-oriented soluble epoxide hydrolase (sEH) inhibitors. The described reaction avoids the use of the corresponding amine as counterpart. The obtained ureas are characterized by reduced melting points and improved solubility in water.