Mechanism of the recyclization of 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one into derivatives of 2-amino-5-benzylidene-1,5-dihydro-4H-imidazol-4-one

Mechanisms are given for reactions taking place upon heating 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one in a medium consisting of a secondary amine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 111–114, January, 2008.     

Heterocycles with a Bridged Nitrogen Atom. 13. An Anomalous Example of the Sulfonating Action of Dimethyl Sulfate During an Attempt at the Methylation of 5-Aminoindolizine. Crystal Structure of Methyl 5-Morpholyl-2-(p-nitrophenyl)indolizine-1-sulfonate

The reaction of 5-morpholino-2-(p-nitrophenyl)indolizine with dimethyl sulfate gives the sulfonation product - methyl 5-morpholyl-2-(p-nitrophenyl)indolizine-1-sulfonate. Its structure was proved by X-ray crystallographic analysis.     

N-Methylimidazolium perchlorate as a new ionic liquid for the synthesis of bis(pyrazol-5-ol)s under solvent-free conditions

N-Methylimidazolium perchlorate([MIm]ClO₄) was synthesized and some of its physico-chemical properties, such as density, surface tension were investigated. A thermo gravimetric analysis(TGA) and solvent performance were also studied. The results show that this ionic liquid is an excellent catalyst for the synthesis of 4,4'-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives under solvent-free conditions. This method has the advantages of high yield, clean transformation, simple operation and short reaction time. The ionic liquid can be recycled without significant loss of activity.     

Photochromic Dihetarylethenes. 8. A Novel Route to the Synthesis of 3,4-Bis(2,5-dimethyl-3-thienyl)furan-2,5-dione as a Potential Photochrome

There is proposed, and in the case of 2,5-dimethylthiophene carried out, a novel route to the synthesis of 3,4-dithienylfuran-2,5-dione type photochromes. This is done in two stages, the first being a Friedel-Crafts reaction of the starting thiophene with the dichloride of squaric acid and the second is a Baeyer-Villiger oxidation of the 3,4-bis(2,5-dimethyl-3-thienyl)cyclobutenedione to give the target 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione.     

Heterocyclic Compounds with a Bridge Nitrogen Atom. 14. Cycloaddition of Acetylenedicarboxylic Acid Ester to 2-Chloro-N-phenacylpyridinium Ylide. Crystal Structure of Dimethyl Ester of 5-Chloro-3-(p-nitrobenzoyl)indolizine-1,2-dicarboxylic Acid

Derivative of 5-chloroindolizine is formed in the reaction of 2-chloro-1-(p-nitrophenacyl)pyridinium ylide with acetylenedicarboxylic acid dimethyl ester, the structure of which was demonstrated by X-ray diffraction analysis. According to data of ¹H NMR and mass spectra indolizine obtained undergoes an unusual intramolecular cyclization with the formation of benz[e]cycl[3.3.2]azine nucleus.     

Study of the behavior of p-bis{3-[N,N-dialkyl-N-(4-hydroxybut-2-ynyl)ammonio]prop-2-ynyl}-benzene dichlorides in relation to aqueous alkali. Double intramolecular recyclization of benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium dichlorides

p-Bis{3-[N,N-dialkyl-N-(4-hydroxybut-2-ynyl)ammonio]prop-2-ynyl}benzene dichloride in the presence of catalytic amounts of aqueous alkali is subject to a double intramolecular cyclization forming benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium dichloride in 40–42% yield. Simultaneously an intramolecular recyclization takes place with the formation of dialkyl(6-dialkylaminomethyl-7,9,10,12-tetrahydro-8,11-dioxadicyclopenta[c,g]phenanthren-1-ylmethyl)amines in 7–9% yield. The same compounds are obtained in 70–72% yield by the recyclization of benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium dichlorides under conditions of aqueous alkaline degradation. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1329–1335, September, 2006.     

Pheromone synthesis. Part 244: Synthesis of the racemate and enantiomers of (11Z,19Z)-CH503 (3-acetoxy-11,19-octacosadien-1-ol), a new sex pheromone of male Drosophila melanogaster to show its (S)-isomer and racemate as bioactive

The enantiomers of (11Z,19Z)-3-acetoxy-11,19-octacosadien-1-ol were synthesized from the enantiomers of 3,4-epoxy-1-butanol PMB ether. Its racemate was also synthesized. Its (S)-isomer and racemate were shown to possess the same pheromone activity as CH503, a long-lived inhibitor of male courtship in Drosophila melanogaster, although the racemate was less active.