Wyniki wyszukiwania - BazTech

1

Derywatyzacja w chromatografii gazowej. Przegląd metod i reagentów

Haliński Łukasz

Laboratorium - Przegląd Ogólnopolski

|

2020

|

nr 3

14--21

PL

Synteza pochodnych (derywatyzacja) to kluczowy etap wielu metod analitycznych wykorzystujących chromatografię gazową. Pozwala na zwiększenie lotności oraz stabilności termicznej analitów, a także ułatwia identyfikację substancji. W artykule przedstawione są najważniejsze metody syntezy pochodnych oraz przegląd powszechnie stosowanych reagentów. Wskazane są także możliwe drogi rozwoju analityki w tym obszarze.

EN

Derivatization is a key stage of many analytical procedures that utilize gas chromatography as an analytical technique. lt enables increasing the volatility and thermal stability of analytes, and sometimes facilitates their identification. The most important methods of derivatization and widely used reagents are described in this short review. Perspectives of the further progress in this field are also briefly discussed.

2

Nowa bezrozpuszczalnikowa metoda syntezy olanzapiny i jej pochodnych

Jaśkowska J., Kułaga D., Majka Z.

Przemysł Chemiczny

|

2016

|

T. 95, nr 10

1918--1920

PL

Opracowano nową bezrozpuszczalnikową metodę syntezy olanzapiny w reakcji jodku metylu i N-demetyloolanzapiny (2-metylo-4-(piperazyn-1-ylo)-10H-tieno[2,3-b][1,5]benzodiazepiny) w warunkach promieniowania mikrofalowego. Reakcję prowadzono w obecności węglanu potasu, bromku tertbutyloamoniowego oraz niewielkich ilości dimetyloform- amidu. Uniwersalność i skuteczność nowej metody potwierdzono w syntezie wybranych pochodnych olanzapiny.

EN

2-Methyl-4-(1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine (N-demethylolanzapine) was alkylated witch MeI in presence of K₂CO₃, Bu4NBr and DMF at room temp. in microvawe field to olanzapine and its derivatives. The addn. of DMF resulted in increasing the product yield. The maximum product yield 64% and purity (after 15 s) were reached at equi-mol. N-demetylolanzapine/Mel ratio.

3

Rola różnych rodzajów selektywności kształtu w katalizie, na przykładzie otrzymywania izomerów diizopropylonaftalenu

Brzozowski R.

Chemik

|

2016

|

Vol. 70, nr 6

310--317

PL

Reakcje otrzymywania izomerów diizopropylonaftalenu (DIPN) lub reakcje z ich udziałem są znakomitym przykładem różnych rodzajów selektywności kształtu, jak selektywność substratowa, selektywność produktowa czy selektywność w stosunku do kompleksów stanu przejściowego. Udowodniają one też ważną rolę wejść do porów w powstawaniu różnych produktów reakcji. Z drugiej strony, przy użyciu katalizatorów mezoporowatych, niewykazujących selektywności kształtu, można otrzymać mieszaninę DIPN spełniającą kryteria dla wysokojakościowego rozpuszczalnika.

EN

Reactions of diisopropylnaphthalene (DIPN) synthesis or reactions they take part in are an excellent example of various types of shape-selectivity, namely substrate selectivity, product selectivity, or transition state selectivity. These reactions prove also an important role of pore entrances during formation of reaction products. On the other hand, a mixture of DIPN isomers for application as a high-quality solvent can be obtained on non-shape-selective mesoporous catalysts.

4

Nowe aspekty alkilowania aryloacetonitryli w warunkach katalizy międzyfazowej

Fedoryński M., Jezierska-Zięba M., Kąkol B.

Przemysł Chemiczny

|

2009

|

T. 88, nr 8

872-876

5

Zeolites as the Modern Catalysts for the High Octane Gasoline Component Production

Patrylak K. I., Patrylak L. K., Ionin V. O., Voloshyna Y. G., Skubiszewska-Zięba J., Repetskyi I. A.

Polish Journal of Chemistry

|

2008

|

Vol. 82, nr 1-2

101-106

EN

Processes of isobutane with butenes alkylation with the purpose of obtaining the high octane gasoline component (alkylate), being environmentally detrimental due to use of concentrated H2SO4 or HF acids as catalysts, are nevertheless of great industrial importance supplying the world market with approximately 80 mln tons of alkylate yearly. The perspective of zeolite catalysts as the substitutes of the above concentrated acids in the modern alkylation process has been considered. The most effective today’s solid alkylation catalyst of the narrow acid spectrum has been found. Such acidity spectrum is considered to be responsible for the essential prolongation of the effective catalyst lifetime.

6

Transformation of Tertiary Amines into Alkylating Reagents by Treatment with 2-Chloro-4,6-dimethoxy-1,3,5-triazine. A Synthetic Application of Side-Reaction Accompanying Coupling by Means of 4-(4,6-Dimethoxy-[1,3,5]triazin-2-yl)-4-methyl-morpholin-4-ium

Kolesińska B., Kamiński Z. J.

Polish Journal of Chemistry

|

2008

|

Vol. 82, nr 11

2115-2123

EN

Mild reaction conditions are described for the preparation of a number of alkyl chlorides and 2-dialkyl(aryl)amino-4,6-dimethoxy-1,3,5-triazines by dealkylation of quaternary triazinylammonium chlorides formed as reactive intermediates in reaction of tertiary amines with 2-chloro-4,6-dimethoxy-1,3,5-triazine. The high selectivity of substitution was observed within the reactivity order of the alkyl groups: benzyl ~ allyl > methyl > n-alkyl. Studies on dealkylation of S-(-)-dimethyl-(1-phenylethyl)amine to R-(+)-1-chloro-1-phenylethane revealed that reaction proceeded with an inversion of configuration on the carbon atom as may be expected for SN2 type substitution. The scope of reaction was extended by exchange of anion in quaternary triazinylammonium chlorides with I-, SCN-, C6H5O-, CH3COO- followed by N-dealkylation step.

7

Recent Development of the Cyclopropanol Methodology for the Preparation of Methyl or Methylene Branched Natural Compounds

Bekish A., Prokhorevich K., Pritytskaya T, Kulinkovich O.

Polish Journal of Chemistry

|

2006

|

Vol. 80, nr 4

549-558

EN

Syntheses ofmethyl andmethylene branched natural compounds based on the ring-forming and subsequent ring-opening reactions of strained three-membered ring of cyclopropanol intermediates are reviewed.

8

Mild Conditions Synthesis of Mixed Organic Peroxides from Alkyl Halides and Organic Hydroperoxides

Baj S., Krawczyk T., Siewniak A., Rączkowska A.

Polish Journal of Chemistry

|

2004

|

Vol. 78 / nr 3

381-384

EN

The synthesis of mixed organic peroxides by reaction of alkyl halides with tertiary hydroperoxides under basic phase-transfer catalysis conditions was described.

9

Simple Approach to 1-Alkyl-2-isopropylhydrazines

Zawadzki S., Zwierzak A.

Polish Journal of Chemistry

|

2003

|

Vol. 77 / nr 3

315-319

EN

Ditosylates of 1-alkyl-2-isopropylhydrazines were prepared by N-alkylation of t-butyl isopropylidenecarbazate (2) followed by reduction of N-alkyl-t-butyl isopropylidenecarbazate (3) with lithium aluminum hydride in boiling tetrahydrofuran. The removal of N-Boc protecting group was quantitatively achieved by refluxing N-alkyl-t-butyl isopropylcarbazate (4) with p-toluenesulfonic acid monohydrate in dichloromethane.

10

Podstawy technologii produkcji fenolu i acetonu metodą kumenową. Cz. 1 Alkilowanie benzenu propylenem

Lewandowski G., Milchert E.

Przemysł Chemiczny

|

2001

|

T. 80, nr 3

113-118

11

Zastosowania reakcji Mitsunobu w chemii aminokwasów

Wiśniewski Kazimierz, Kołodziejczyk Aleksandra S., Falkiewicz Bogdan

Wiadomości Chemiczne

|

1998

|

[Z] 52, 3-4

243--267

EN

The Mitsunobu reaction has been knowm since the late sixties. It is mediated by the redox system : triaryl - or trialkylphosphine/dialkyl azodicarboxylate and brings about the nucleophilic substitution of an alcoholic hydroxyl group by the conjugate base of an acidic reactant, with inversion of configuration at the alkohol carbon. The Mitsunobu reaction is widely used in organic chemistry and its mechanism (Scheme 1) has been intensively studied (for review - see [2-5]). This article deals with the application of the reaction in the chemistry of amino acids. The reaction was proposed as an effective method of a-amino acid synthesis using hydroxy acids as substrates. As the amino group synthons phtalimide [10, 11], (Scheme 2), hydrazoic acid [14], (Scheme 5) or t-butyl-2(trimethylsilil)ethylsulphonylcarbamate [18], (Scheme 7) were used. The procedure using HN3 was profoundly improved by the introduction of a stable bis-pyridine complex of zinc oxide [16]. The use of phtalimide as an amino group precursor in Mitsunobu-type reaction was successfully applied to the synthesis of 2-2H-labelled chiral glycine [13], (Scheme 4). In the model studies on the synthesis of 15N-labelled N-protected chiral amino acids Degerbeck et al. [17] found that the yield of the Mitsunobu conversion (Scheme 6) depends on the acidity of the NH function in the imidocarbonate or sulphonylcarbamate used. The Mitsunobu reaction has also been applied to the synthesis of many unnatural or modified amino acids such as protected 2,3-diamino butyric acid [19], 3- or 4- mercaptoproline derivatives [20, 21], (Scheme 8), N5-acetyl-N5-hydroxy-L-ornitine [22], (Scheme 9) and a-N-hydroxyamino acids [23], (Scheme 10). Wojciechowska et aal[24] have reported the preparation of dehydroamino acids from protected serine and threonine derivatives under the intramolecular Mitsunobu dehydration condition (Scheme 11). A general approach to the preparation of N-monoalkylated amino acids based on the Mitsunobu reaction has been developed [3-] using N-tosylamino acid esters as acidic components of the reaction (Scheme 15). Since the removal of tosyl group is difficult, a modification of the N-alkylation procedure has recently been devised [32, 33]. The Mitsunobu reaction is also an excellent procedure for transforming hydroxy acids or hydroxy amino acids into esters whose subsequent hydrolysis leads to a stereoisomer of the initial compound with the inverted configuration at the carbinol centre and was very often used in this way [37, 38], (Schemes 8 and 17). The Mitsunobu reaction provides also an interesting method of esterification in which an alcohol, not a carboxylic component, is activated. It was used to the synthesis of diphenylmethyl esters of N-trityl amino acids [43], to the attachment of a first amino acid to the polymer support [44] or to active ester synthesis [45], (Scheme 18). The applications of the Mitsunobu reaction include also the preparation of amny cyclic derivatives of amino acids such as B-lactams [51], (Scheme 20), aziridines [49, 54], (Schemes 19, 21) or B-lactons [60]. The last cyclic derivatives are valuable intermediates for the synthesis of B-substituted alanines (Scheme 22). B-Lactonization proceeds easily in case of serine derivatives whereas in threonine derivatives B-elimination is the dominant reaction [61], (Scheme 23). The review deals also with the application of the title reaction to the synthesis of peptide (polyamide) nucleic acids (PNA) [31, 39, 40, 68-70].

12

Ambiphilic reactivity of 2,4-dinitrobenzyl p-tolyl sulfone carbanion

Mąkosza M., Mathur S.N., Białecki M.

Polish Journal of Chemistry

|

1998

|

Vol. 72, nr 7

1198-1201

EN

Carbanions of 2,4-dinitrobenzyl p-tolyl sulfone (3a) and 5-chloro-2,4-dinitrobenzyl p-tolyl sulfone (3b) behave as ambiphilic reagents able to react with nucleophiles and electrophiles. The reaction course depends on the type of the reagent and of the base used in the reaction.