摘要:

Selectivity: OH‐, NH‐ and SH‐Groupspecific Reagents. The Application in Organic Analysis and as Protective GroupsPhosphylhalides and ‐pseudohalides R1R2P(O)X (X = Cl, F, CN, N3, OC6H4NO2(p)) reactdepending on X‐ with a different selectivity with OHNH‐ and SH‐groups. Vinylsulfones ArSO2CH = CH2are SH‐selective. Silanes R3SiH are OH‐selective.By exchange of one ligand bound on P, SO2or Si by the 5‐dimethylamino resp. the 5‐methoxynaphthalinogroup reagents are formed, which combine group selectivity with fluorescence. The fluorescence is quenched if a ligand or the leaving group is substituted by a NO2‐group.The fluorescence appears again if after the group selective fixation the ligand with the nitrogroup is split off.In serine enzymes (α‐chymotrypsine, trypsin, butyryl‐ and acetylcholinesterase, subtilisine) and insuline (after the reductive opening of the S‐S bridges) the primary OH‐groups in the active site in the enzymes resp. the SH groups in the reduced insuline were substituted with fluorescing groups using grou

ISSN:0941-1216    

DOI:10.1002/prac.19923340802

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractVia a metal ion template directed synthesis and a high dilution cyclization, a bimacrocyclic 4‐benzyloxyethoxy‐substituted concave pyridine8was synthesized from dialdehyde3, diamine4and diacyl dichloride7in 54% overall yield. Pd‐catalyzed hydrogenolysis of8afforded the OH‐substituted concave pyridine9which could be attached to a Merrifield resin10after deprotonation with NaH. The modified polymer11contained 10% (w

ISSN:0941-1216    

DOI:10.1002/prac.19923340803

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractIsocyanates react asN‐nucleophileswith α‐chlorobenzylic cations (2) to give 1‐oxoisoindolium salts (5). From the reaction of benzotrichlorides with SbCl5and isocyanates the extremely reactive hexachloroantimonates5with R2= Cl are isolated. Hydrolysis of these cyclic N‐acyl iminium salts affords phthalimides6. Reaction of5 kwith dimethylcyanamide gives the 2‐azoniaallene salt13. p‐Tolyl isocyanate isFriedel‐Craftsalkylated by p‐chlorobenzotrichloride (1i) in the presence of SbCl5to furnish the 1,3‐oxadiazinium salt7, which is hydrolyzed to give the benzophenone9. With ethanol the acetals10and

ISSN:0941-1216    

DOI:10.1002/prac.19923340804

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractTrichlormethanes4react with two equivalents of n‐alkyl isocyanates R2‐NCO in the presence of SbCl5to furnish the 2,2‐dichloro‐5,6‐dihydro‐6‐oxo2H‐1,3,5‐oxadiazinium salts (9). The structure of these heterocycles is confirmed by an X‐ray analysis of9d(R1= ClC = CCl2, R2= Et). p‐Tolyl isocyanate is Friedel‐Crafts alkylated by4bin the presence of SbCl5. Subsequent ring closure affords the quinolinium salt13, which is hydrolyzed to givein

ISSN:0941-1216    

DOI:10.1002/prac.19923340805

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

FTIR‐spectroscopic Investigations of the Structure of Polyamino Acid‐Peptide Hormone ComplexesThe hormone release from polyamino acid complexes depends on the nature of intermolecular interactions between the hormone and the complexing compounds. By differential FTIR‐spectroscopy of complexes and mixtures of the two compounds, conformative alterations have been observed especially in the complex forming polyamino acid‐peptide inter

ISSN:0941-1216    

DOI:10.1002/prac.19923340806

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Adsorption of Vinyl Chloride on Activated Carbons, Adsorber Polymers and Zeolites. II. Kinetics of AdsorptionChlorinated hydrocarbons are a source of danger to the environment. Therefore they have to be eliminated. Adsorption processes seem to be most effective for the separation of vinyl chloride from the air. In this paper the adsorption of vinyl chloride on activated carbon, adsorber polymers or zeolites has been investigated in order to determine kinetic data by a gravimetric adsorption apparatus. These data have been applied to calculate of effective diffusion coefficients using an approximation of Fick's second law. The calculated diffusivities show a dependence on the amount adsorbed, the structure and the properties of the adsorbent.

ISSN:0941-1216    

DOI:10.1002/prac.19923340807

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Cycloaddition Elimination Reactions of Phenylisocyanate with Oxo and Thiono Derivatives of Aliphatic Substituted 5‐Imino‐1,2,4‐dithiazolidines and 3‐Thiono‐1,2,4‐thiadiazolidines (Mustard Oil Oxides and Sulfides)5‐Imino‐1,2,4‐dithiazolidin‐3‐ones1and‐3‐thiones3react with phenylisocyanate to afford 5‐imino‐1,2,4‐thiadiazolidin‐3‐ones6. In comparison isomeric 3‐thiono‐1,2,4‐thiadiazolidin‐5‐ones2,5, and ‐5‐thiones4yield 3‐imino‐1,2,4‐thiadiazolidin‐5‐ones8,10, and ‐5‐thiones7. Thermolyses of thiadiazolidines5and10afford further 1,2,4‐thiadiazolidines9,11. Compounds8–11are available also by reac

ISSN:0941-1216    

DOI:10.1002/prac.19923340808

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractAn equation describing the relationship between the research octane number (RON) and the1H‐and13C‐NMR is proposed. This equation relates the RON to the aliphatic, olefinic and aromatic hydrogen and carbon, respectively. To check this relationship 60 samples were investigated with RON values between 65 and 96. The fitting procedure yielded good agreement between the RON measured with the ASTM method and the RON calculated from both the1H‐and the13

ISSN:0941-1216    

DOI:10.1002/prac.19923340809

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Synthesis and1H‐NMR Spectroscopic Investigations of New Curcumin AnalogaThe synthesis of numerous symmetric and non‐symmetric curcumin(hetero) analoga (1–3) systematic variation of the conjugated chain and substituents is described. The structure of most compounds is confirmed by1H‐n.m.r.‐spectroscopy. All compounds show E‐configuration. Conjugation and tautomerism are discussed based on spectro

ISSN:0941-1216    

DOI:10.1002/prac.19923340810

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Mixing Functions of the Binary System N‐Methylcaprolactam – n‐TetradecaneThe liquid‐liquid equilibria(LLE) and the vapour‐liquid equilibria(VLE) at 60°C were measured in the binary system N‐methylcaprolactam (1) – n‐tetradecane (2). The enthalpy of mixing HEof the same system was extrapolated from HE– measurements of N‐methylcaprolactam with other alkanes. The limiting activity coefficients f∞1and f∞2were obtained by extrapolation from values of resp. in other alkanes. For a comparison the vapour pressures of the mixture were calculated by model equations with constants from the two limiting activity coefficients and with temperature dependent constants extracted from th

ISSN:0941-1216    

DOI:10.1002/prac.19923340811

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY