Fractals and generalized inner products

The generation of fractals by a generalization of the matrix product is described. These matrix products allow visualization of additional structure of the fractals as well as producing fractals of new types.     

Solubility enhancement of triflumizole by host-guest interaction with β-cyclodextrin

Summary The solubility enhancement of triflumizole, a systemic fungicide, by -cyclodextrin inclusion complexation was investigated by electron absorption spectroscopy. The respective association constant determined by different methods was estimated to 470±20M ^–1 in aqueous solution. A model for the host-guest complexation was deduced by molecular calculations.

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Löslichkeitsverbesserung von Triflumizole durchHost-Guest-Complexierung mit -Cyclodextrin

Zusammenfassung Die Löslichkeitsverbesserung des systemischen Fungizids Triflumizole durch Komplexierung mit -Cyclodextrin wurde mittels Elektronenabsorptionsspektroskopie untersucht. Die entsprechende Stabilitätskonstante wurde durch verschiedene Methoden erfaßt und betrug im wäßrigen Medium 470±20M ^–1. Ein Model für denHost-Guest-Complex wurde durch Molekülrechnungen erstellt.

     

On triazoles. VII Synthesis of novel tri- and tetracyclic ring systems

The ring-closure of the 5-amino-1-(2-aminophenyl)-3-methylthio-1H-1,2,4-triazole derivatives 3 and 4 with different simple and cyclic C₁ components lead to the formation of 1,2,4-triazolo[1,5-α]-1,3,5-benzotriazepines 5–6 , their 4,5-dihydro- 7 , different 5-spiro-homocyclic- 8–13 , and 5-spiro-heterocyclic- 14-15 analogues. The structure of the compounds obtained was proved with the use of their ir, uv, ¹H-nmr and ¹³C-nmr spectra.     

Chromatographic competitive binding immunoassays: a comparison of the sequential and simultaneous injection methods

Two approaches for performing competitive binding immunoassays by HPLC and other flow-based systems are the simultaneous and sequential injection methods. Both these techniques make use of a column with a limited amount of antibody, onto which is injected a sample and a fixed amount of a labeled analyte analog. An indirect measure of the unlabeled analyte in the sample is then obtained by looking at the amount of analog in either the nonretained or retained peaks. In the simultaneous injection mode, the sample and labeled analog are applied at the same time to the column, while in the sequential mode the sample is injected first, followed by the analog. This results in a difference in the analytical characteristics of these two approaches. This study used chromatographic theory and previous data obtained for injections of human serum albumin (HSA) onto an anti-HSA antibody column to compare the response, detection limits, range, and sensitivity of these methods. Under equivalent conditions, it was found that the sequential method always provided the best lower limit of detection and sensitivity. However, the simultaneous mode had a broader dynamic range and higher upper limit of detection. From these observations, several guidelines were developed regarding the use and selection of such assays for new applications.     

On triazoles XXXVIII. The reaction of isomeric 5-amino-3-morpholino-1H-1,2,4-triazolylcarbothiohydrazides with ortho esters

The reaction of isomeric differently methylated 5-amino-3-morpholino-1H-1,2,4-triazolylcarbo-thiohydrazides with ortho esters were studied. Except of the case of triethyl orthoacetate instead of the expected [1,2,4]triazolo[1,5-d][1,2,4,6]tetrazepin-5(7H)-thione ( 6 ) derivatives different rearranged products such as 7, 8, 21, 23, 25 , and 27 were obtained, derivatives 23 and 27 representing a novel ring system. Possible explanations were given for the formation of the rearranged products.     

Palladium-catalyzed oxidative cyclizations: synthesis of dihydropyranones and furanones

A boron-mediated syn- and anti-stereoselective aldol reaction giving rise to various beta-hydroxyenones was coupled to a Pd((II))-mediated oxidative cyclization to give 2,3,6-trisubstituted syn- and anti-dihydropyranones in good yields. The Pd((II))-mediated oxidative cyclization was expanded to alpha-hydroxyenones leading to furan-3(2H)-one derivatives, which include natural product bullatenone and a known precursor of geiparvarin. The sole product of the oxidative cyclization of alpha,beta-dihydroxyenone was a five-membered furan-3(2H)-one derivative, suggesting that the ring closure of these diols is both chemo- and regioselective.     

Synthesis of C-nor-heterocyclic steroid analogues

2-Substituted-amino-10H-thiazolo[5,4-b]benz[e]indene derivatives 5 representing a novel ring system were synthesized. Their acylation led to exo-acylated derivatives 9 that could be converted to the corresponding glycine analogues 12 .     

On triazoles. XXXIV. The correct structure of the ethoxycarboxylated 5-amino-1H-1,2,4-triazole and its product with hydrazine

The structure of the ethoxycarboxylated product of 5-amino-1H-1,2,4-triazole and its hydrazide was corrected using their ir, pmr, cmr and mass spectra.     

On triazoles XLIX. Synthesis of 5,6‐dihydrothiazolo[3,2‐b]‐[1,2,4]triazol‐2‐yl‐, 6,7‐dihydro‐5H‐[1,2,4]triazolo[5,1‐b][1,3]thiazin‐2‐yl‐, and 5,6,7,8‐tetrahydro[1,2,4]triazolo[5,1‐b] [1,3]thiazepin‐2‐yl‐isoquinolinium salts

5′‐Mercapto‐1′H‐1,2,4‐triazol‐3′‐yl‐isoquinolinium salts (6) were synthesised by the reaction of ortho‐acyl phenylacetones (2) or the corresponding pyrylium salts (3) and 5‐amino‐2,3‐dihydro‐1H‐1,2,4‐triazole‐3‐thione (5) . Treatment of thioles 6 withα,ω‐dibromoalkanes led to type 15, 16 and 17 isoquinolinium salts condensed with thiazole, thiazine and thiazepine rings. When 6 are reacted with dibromomethane (10) 11 type dimeric structures are obtained.