A racemic mixture of trans-1,2-cyclohexanediol (CHD) is reacted with S,S- or R,R-tartaric acid in ethanol with a 0.5 or higher molar ratio of resolving agent to racemic CHD. The tartaric acid (TA) forms a diastereomeric cocrystal with only one of the enantiomers; the other enantiomer remains unreacted at any molar ratio. The unreacted mixture of enantiomers is recovered from the sample by supercritical fluid extraction at 20 MPa and 33 degrees C. A subsequent extraction is then performed at 20 MPa and at least 73 degrees C. During this second extraction step, the diastereomeric cocrystal is decomposed in situ. Both enantiomers are recovered in nearly 50-50% yield with enantiomeric excess values of 65-90%. The mixtures of enantiomerss rich in S,S-CHD and R,R-CHD are then reacted with S,S-TA and R,R-TA, respectively, and the procedure is repeated. In two resolution steps, both enantiomers of CHD were produced in quantitative yields in a purity of ee > 99%.

In this work the utility of new possible petrochemical feedstocks obtained by plastic waste cracking has been studied. The cracking process of polyethylene (PE), polyethylene-polypropylene (PEPP) and polyethylene-polystyrene (PEPS) has been carried out in a pilot scale tubular reactor. In this process mild reaction parameters has been applied, with the temperature of 530 degrees C and the residence time of 15 min. The produced hydrocarbon fractions as light- and middle distillates were tested by using a laboratory steam cracking unit.It was concluded that the products of the mild cracking of plastic wastes could be applied as petrochemical feedstocks. Based on the analytical data it was determined that these liquid products contained in significant concentration (25-50 wt.%) of olefin hydrocarbons. Moreover the cracking of polystyrene containing raw material resulted in liquid products with significant amounts of aromatic hydrocarbons too. The steam cracking experiments proved that the products obtained by PE and PEPP cracking resulted in similar or better ethylene and propylene yields than the reference samples, however the aromatic content of PEPS products reduced the ethylene and propylene yields. (C) 2010 Elsevier B.V. All rights reserved.

A hydrogenation process for the preparation of 4,6-diamino resorcinol from 4,6-bisphenylazo resorcinol was studied and developed up to pilot scale. The high reaction rate together with the protection of the product against oxidation could ensure providing the addition of HCl was made after the fast hydrogenation period. Activity and lifetime of commercial catalysts were evaluated also.

An ecofriendly, microwave (MW) promoted and solventless method is described for the alkylation of diethyl malonate, ethyl acetoacetate and ethyl cyanoacetate by a variety of alkyl halides in the presence of K2CO3. In the solid-liquid phase alkylation of active methylene containing substrates, it seems to be of general value that the phase-transfer catalyst, that is an onium salt in the present case, can be omitted and substituted by MW irradiation promoting the formation of the potassium salt of the substrate and its transfer to the organic phase. In certain cases, the use of triethylbenzyl-ammonium chloride led to the formation of by-products under the conditions (similar to 160 degrees C/similar to 12 bar) applied.

The coupling reaction of phenylboronic acid with 4-silyl-bromobenzenes incorporating an ionic liquid support or its neutral analogue at 80 °C in DMF/H 2 O in the presence of Pd(PPh 3 ) 4 and Na 2 CO 3 takes place much faster and more efficiently under microwave irradiation than under traditional heating.It is an attractive method to carry out the generally slow Suzuki-Miyaura reactions under microwave conditions.

Studies have been made in heterogeneous hydrogenations on the possible enantioselective effects of precursors of binol-phospates, which proved to be active and effective chiral ligands in homogeneous catalysis. It was to find out, whether a modifier with axial chirality could be used in heterogeneous hydrogenations if it meets certain structural requirements. Our results show that while the conversions reach 100%, the enantiodifferentiation was negligible.

A kutatomunka elsősorban a prolin nitrogenen alkilezett szarmazekainak előallitasara es ezekből eszteresitessel kondenzalt aromas szarmazekaik szintezisere iranyult. A feladat celkitűzese onnan ered, hogy voltak korabbi kiserleteink a karboxil csoportjan eszteresitett prolinnal, mint kiralis modositoval, ezeket az igeretes molekulakat akartuk tovabbfejleszteni oly modon, hogy a nitrogenen alkilezzuk őket. Az alkilezesre a reduktiv alkilezes modszeret valasztottuk es olyan ketonokat (izoforon, etilpiruvat, benzalaceton) hasznaltunk, amelyek prokiralisak. Az alkilezett prolin szarmazekok alkil csoportja pedig az enantioszelektiv reakcioban hidrogenezendő vegyuletekből szarmazik. Ezzel a reszolvalasnal jol ismert, un. ?sajat szarmazek hatast? akartuk tanulmanyozni, javitja-e a szubsztratum molekulahoz hasonlo alkil csoport a kiralis modosito hatast. Előallitottuk a tiszta 3,3,5-trimetilciklohexanont es ennek tiszta enantiomerjeit is. Tovabba a reduktiv alkilezessel megkaptuk az N-(3,3,5-trimetilciklohexil)prolint is enantiomertiszta formaban. A kiserleti eredmenyek alapjan valoszinűsitettuk a reakcio mechanizmusat. | The aim of the research was to synthesize the alkylated derivatives of proline and its condensed aromatic derivatives with esterification. This objective originated from our earlier experiments with proline esters as chiral modifiers. These promising molecules could be developed further with alkylation at their N atom. Reductive alkylation was the method of choice, for alkylation such ketones were chosen (isophorone, ethyl pyruvate, benzilydene acetone) which are prochiral. The alkyl group is originating from those substrates, which are hydrogenated in the asymmetric reactions. With this method we wanted to study the so called ''own derivative'' effect which is known from optical resolution, whether the similar alkyl group improves the asymmetric effect, the chiral modification. The pure 3,3,5-trimethyl cyclohexanone and its pure enantiomers were prepared, furthermore the N-(3,3,5-trimethylcyclohexyl)proline was also the product in enantiomerically pure form. A reaction mechanism was proposed.

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Solid paraffins were steam-cracked in order to imitate the pyrolysis of low polymerization grade polyethylene. The behavior of the paraffins in steam-cracking corresponds to that of gasolines due to the similar C/H ratio.

Steam cracking of several gasoline and gas oil samples was carried out under different conditions and the results are reported. Some of sample feedstocks were previously cracked in a commercial plant so the laboratory and commercial results could be compared. It was found that the laboratory reactor was more sensitive to the changes of the composition of the raw materials.

Simple CH-acidic compounds can be easily monoalkylated in solid-liquid phase in the absence of a phase transfer catalyst applying microwave under solvent-free conditions.

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A laboratory steam-cracking reactor was designed, built and tested in order to compare yields under different operating conditions. A typical industrial gasoline was used as feedstock to test the reactor. The design of the reactor was found appropriate to crack hydrocarbon feedstocks and the olefin yields follow the expected trends.

The milk composition of high-yielding dairy cows is highly related to their nutrition. The energy deficiency in dairy cows can cause subclinical or clinical ketosis. In ketotic state the concentration of ketone bodies (acetone, AC; acetoacetic acid, ACAC; and β -hydroxybutyric acid, BOHB) increases in the different body fluids and simultaneously, changes in concentration of other compounds are also expected. The authors´ hypothesis is that the members of the TCA-cycle, such as citric acid (CA) also change in association of increased formation of ketone body. To support this hypothesis the concentrations of ketone body components and CA were parallel measured and their relationship was studied in raw milk samples. Based on the AC concentration of the milk samples two groups were formed retrospectively: High Acetone (HA) Group ( n=41 ) of AC concentration >0.4 mM and Low Acetone (LA) Group ( n=78 ) with the AC level ≤ 0.4 mM. In all samples very low ACAC level was found, which is a consequence of the spontaneous decarboxylation of ACAC to AC during the usual sample storage. Focusing on the results of HA Group the authors found significant relationship between CA and ketone bodies and a parallel drop of AC and CA during the metabolically crucial first 1-4 weeks of lactation. For this reason they suggest to introduce simple, easy, automated methods to determine AC and/or CA concentration in raw milk.

AbstractBei Acylierungsreaktionen von Phthalimid mit dem Thiophosphorylchlorid (I) entstehen die beiden Phosphorsäureanhydride (II) und (III) als Nebenprodukte.