摘要:

AbstractThe Reaction Injection Molding (RIM) technology has made it possible to master the fast reaction of di‐ and polyamines with di‐ and polyisocyanates, leading to the preferred polyurea structure. Telechelics with amino end groups are gaining increased interest for the manufacture of polyurethane‐polyurea materials by this technology. They make it possible to substitute all urethane groups in the elastomers with urea groups. The telechelics which are considered are amine‐terminated polyethers (ATPE) and polyesters based on the typical soft‐segment forming polycondensation polymers which are widely used in polyurethane chemistry.Isocyanate‐terminated prepolymers of toluene diisocyanate and polyether polyols can be hydrolyzed in aqueous alkaline media via the carbamate intermediate to the amineterminated prepolymers. The reactivity of these aromatic ATPEs was ideally fit for the RIM process. ATPEs by the hydrolysis process are somewhat limited if products with low viscosities are required. In the reaction of chloro‐nitrobenzenes with polyether polyols followed by the hydrogenation of the nitro groups of the terminal phenoxy moieties, we found a path for the synthesis of low viscosity aromatic ATPEs. Capping of polyether polyols with acetoacetate groups and subsequent reaction of the acetoacetylated polyethers with amines, leads to polyethers with terminal imine or enamine groups, which are derivates of aminocrotonic acid. We determined that this approach is a universal method for the synthesis of a large variety of aromatic as well as aliphatic ATPEs with low viscosities. Trifluoroacetic acid turned out to be the ideal catalyst for the reaction of the acetoacetylated polyethers with aromatic diamines, one amino group forming the imine link, the second one remaining intact and providing the desired reactivity towards isocyanates. Aliphatic diamines do not require a catalyst for this reaction. They lead to aminocrotonates with aliphatic amino groups that have high reactivity towards isocyanates, which is to be expected from aliphatic amines. The reaction of the chloroformates of polyether polyols with diamines can also be used to synthesize a variety of ATPEs. We recently developed an approach to low viscosity ATPEs having secondary amino end groups. The hydroxyl groups of the polyether polyols are converted to chloride or methanesulfonyl. The polyethers terminated with these leaving‐groups are reacted with primary aliphatic or aromatic amines to give the secondary ATPEs in v

ISSN:0941-1216    

DOI:10.1002/prac.19943360602

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

Therapeutically Active Phosphonates: Results from 30 Years of Development Concerning Polyphosphonic AcidsDuring the last three decades pharmacologically active phosphonates played a significant role in medical research. Looking for phosphate substitutes in various technical applications, we also dealt, to a limited extent, with this topic. Newly synthesized complexing agents like hydroxy‐, amino‐ and carboxyl alkane phosphonic acids and derivatives thereof such as cis‐Diammine[nitrilotris(methylphosphonato)(2‐) O1,N1]platinum(II) gave interesting pharmacological applicabilities. Some of them were tested clinically

ISSN:0941-1216    

DOI:10.1002/prac.19943360603

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

1‐Amino‐4‐aryl‐2(1H)‐pyrimidinethiones: Acidity and Complex Formation with Nonferrous Metal Ions and Ag(I)Acid dissociation constants of new2, 3and already known1substituted 1‐amino‐4‐aryl‐2(1H)‐pyrimidinethiones and stability constants of their nonferrous metal ion and silver complexes have been measured pH‐potentiometrically in a 75% (v/v) mixture of dioxane/water. The influence of the substituents on pKa‐ and lgβn‐values is discussed. The X‐ray structure analysis of bis[1‐(4‐toluenesulfonamido)‐4‐(4‐tolyl)‐2(1H)‐pyrimidinethionatol]‐nickel(II)5proves that pyrimidinethiones coordinate via their thione sulphur and aminonitrogen. However, the bond le

ISSN:0941-1216    

DOI:10.1002/prac.19943360604

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

AbstractLucigenin (N,N′‐dimethyl‐9,9′‐biacridinium nitrate)1on heating under reflux in protic solvents in the presence of amines gives rise to the N,N′‐dimethyl‐9,9′‐biacridylidene2(DBA) or protected hemiaminal N‐methoxymethyl‐9,9′‐bi‐acridylidene3. On the other hand acid hydrolysis and synchronous oxidation of hemiaminal3followed by reaction of monomethyl‐biacridinium nitrate4with sodium hydroxide in methanol or water leads to bia

ISSN:0941-1216    

DOI:10.1002/prac.19943360605

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

r‐5‐(α‐Halogenobenzyl)‐3,t‐4‐diaryl‐c‐4‐hydroxy‐oxazolidin‐2‐ones as Ring Tautomers of α‐(N‐Arylaminocarbonyloxy)‐β‐halogeno‐dihydrochalconesThe reaction of chalcone halogenohydrins (1–3) with arylisocyanates does not stop at the stage of the α‐arylaminocarbonyloxy‐β‐halogeno‐dihydrochalcones (7), but the cyclic urethanes4–6are formed. Compound7hwas synthesized independently. The structure and stereochemistry o

ISSN:0941-1216    

DOI:10.1002/prac.19943360606

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe synthesis of the title compounds was carried out by hydrosilylation of 1,4‐dichlorobut‐2‐yne (1) with defined siloxanes (2a‐c) using a platinum catalyst, followed by the reaction of the received 1,4‐dichloro‐2‐siloxanyl‐but‐2‐enes (3a‐c) with primary, secondary and tertiary amines, respectively. N‐Alkyl‐3‐(siloxanyl)pyrrolines (4,5,6) were reacted with alkyl bromides and sultones, respectively. The products were characterized by elemental analysis and13C‐n.m.r.‐spectroscopy and posses remarkable surface activity. The X‐ray crystal structure of N‐ethyl‐3‐(1,1,1,3,5,5,5‐heptamethyltrisiloxan‐

ISSN:0941-1216    

DOI:10.1002/prac.19943360607

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

AbstractA series of new acidochromic 9‐(4‐dialkylaminostyryl)‐acridines (1) were synthesized and characterized by means of elemental analysis, m.p., mass and1H‐NMR‐spectra. The colour change in the presence of perchloric acid and the pKawas investigated. Their photosensitizing ability was tested by oxygen consumption mea

ISSN:0941-1216    

DOI:10.1002/prac.19943360608

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe synthesis of ten new thyrotropin‐releasing hormone analogues (15–24) which contain uncoded amino acids (L‐ and D‐homoleucine, L‐ and D‐homophenylalanine, L‐homoproline and 6‐ketopipecolic acid) is described here. The peptide bond formation was achieved in solution phase using pentafluorophenyl ester activation of the N‐protected amino acids. The analogues were tested for their ability to release thyrotropin and for CNS activities and proved to

ISSN:0941-1216    

DOI:10.1002/prac.19943360609

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

Ansa‐Porphyrines with an Alkyl Chain, a Pyridine or a Second Porphyrine in the BridgePorphyrines1, 2aand2bwith an alkyl chain, a pyridine or an additional porphyrine in the bridge are prepared in yields between 5 and 24% by condensation of appropriate chains5and6containing two terminal benzaldehyde functions with 3,3′‐diethyl‐4,4′‐dimethyl‐2,2'dipyrrylmethane7. The synthesis of the dialdehydes5and6is a

ISSN:0941-1216    

DOI:10.1002/prac.19943360610

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe kinetic resolution of tertiary hydroperoxidesviacatalytic Sharpless epoxidation with various allylic alcohols has been investigated. By using 1‐cyclohexyl‐1‐phenylethyl hydroperoxide an enantiomeric excess (e.e.) of up to 29% of the resolved hydroperoxide has been observed at a consumption of the racemic hydroperoxide of nearly 50%. The e.e. can be increased, however, only by raising the hydroperoxide consum

ISSN:0941-1216    

DOI:10.1002/prac.19943360611

出版商:WILEY‐VCH Verlag GmbH    

年代:1994

数据来源: WILEY