Search results for "Condensation reaction"
showing 10 items of 84 documents
An Unexpected Three-Component Condensation Leading to Amino- (3-oxo-2,3-dihydro-1H-isoindol-1-ylidene)- acetonitriles
2004
The reaction of 2-carboxybenzaldehyde with primary amines in the presence of cyanide leads to the formation of 2-substituted amino(3-oxo-2,3-dihydro-1H-isoindol-1-ylidene)acetonitriles. These compounds originate from the condensation of 2-carboxybenzaldehyde with the amine and two molecules of hydrogen cyanide and represent a novel class of isoindolinones.
Versuche zur umsetzung von methylendiphenolen mit glucosederivaten und zur kondensation von O-phenylglucosidderivaten
1981
Attempts to apply known methods of glucosidation to oligo[(hydroxyphenylene)methylene]s were not satisfying. The reaction of 4,4'-dimethyl-2,2'-methylenediphenol (1a) with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide gave a monoglucoside in 11% yield. A second attempt, the condensation of suitable O-phenylglucoside derivatives was unsuccessful. From a series of O-phenylglucosides (4) only 4-(2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyloxy)benzylbromide could be condensed with O-(4-hydroxymethylphenyl)-2,3,4,6-tetra-O-acetylglucopyranose to the corresponding diglucoside of 4,4'-oxydimethylenediphenol (7). Condensation reactions of the O-phenylglucoside 4k, to obtain an O-glucosidized poly[…
Synthesis of pillar[7]arene
2012
Abstract The first synthesis of pillar[7]arene is reported with two methods. Method A: the FeCl 3 -catalyzed condensation reaction of 1,4-dimethoxybenzene ( 1 ) with paraformaldehyde in CHCl 3 gave dimethoxypillar[7]arene ( 3 ). Method B: the p -toluenesulfonic acid catalyzed condensation reaction of 2,5-bis(benzyloxymethyl)-1,4-dimethoxybenzene ( 2 ) in CH 2 Cl 2 gave compound 3 . Demethylation of 3 with BBr 3 gave pillar[7]arene ( 4 ). The pillar[7]arene might be a perspective macrocyclic host in host–guest chemistry.
Verbindungen mit potentiell positiv inotroper Wirkung, 1. Mitt. N-Substituierte 3-Amino-2-cyclopentenone aus partiell hydrierten 2-Phenanthrylaminen
1984
Die Darstellung partiell hydrierter 2-Phenanthrylamine und ihre Umsetzung mit 1,3-Cyclopentandion zu N-subst. 3-Amino-2-cyclopentenonen wird beschrieben. Compounds with Potentially Positive Inotropic Activity, I: N-Substituted 3-Amino-2-cyclopentenones from Partially Hydrogenated 2-Phenanthrylamines The synthesis of partially hydrogenated 2-phenanthrylamines and their reactions with 1,3-cyclopentanedione to N-substituted 3-amino-2-cyclopentenones is described.
Cyclocondensation of alpha-aminonitriles and enones: a short access to 3,4-dihydro-2H-pyrrole 2-carbonitriles and 2,3,5-trisubstituted pyrroles.
2009
The reaction of alpha,beta-unsaturated carbonyl compounds with aminoacetonitrile hydrochloride furnishes 3,5-disubstituted 3,4-dihydro-2H-pyrrole-2-carbonitriles in a one-pot reaction sequence. While these products can serve as starting materials for the preparation of polysubstituted pyrrolizidines, they are kinetically stable against the base-induced elimination of HCN. In contrast, their 2-substituted analogues obtained from alpha-substituted alpha-aminonitriles can be readily converted to the corresponding 2,3,5-trisubstituted pyrroles under microwave irradiation. The key step presumably involves the thermal electrocyclization of a stabilized 2-azapentadienyl anion formed by condensatio…
(E,E,E)-4,4′-Distyrylstilbenes – Synthesis, Photophysics, Photochemistry and Phase Behavior
2008
The fluorescence quantum yields F(n) of oligo[2,5-bis(propyloxy)-1,4-phenylenevinylene]s (1b) reach for the trimer (n = 3) in solution a maximum of 86 %, which is almost twice as high as for the monomer (n = 1) and the octamer or undecamer (n = 8, 11). The latter represent the convergence limit of 46 %. 4-Mono-, 3,4-di- or 3,4,5-trisubstituted terminal phenyl rings in the trimers 6a–f do not lead to calamitic or phasmidic liquid crystals; however, 2,3,4-trisubstitution with hexyloxy groups (6h) and even with OCH3 groups (6g) effects LC formation. Irradiation with energy-rich UV light provokes a crosslinking of the originally conjugated chains. In the case of 6c, a chemo- and stereoselective…
Antidiabetische wirkstoffe. III. 4,5,6-Trisubstituierte 2-(4-toluidino)pyrimidine
1984
Aus der Kondensation von 4-Tolylguanidin (1) mit den β-Diketonen 2a-b gehen die 2-(4-Toluidino)pyrimidine 3a-b hervor. The condensation of 4-tolyiguanidine (1) with the β-kiketones 2a-b yields the 2-(4-toluidino)pyrimidines 3a-b.
Trichomonazide Wirkstoffe, 2. Mitt. Verzweigtkettig 4,6-disubstituierte 2-Cyanaminopyrimidine
1985
Aus der Umsetzung von Dicyandiamid (1) mit den β-Diketonen 2a–b gehen die 4,6-verzweigtkettig disubstituierten 2-Cyanaminopyrimidine 3a–b hervor. Fur Strukturtyp 3 last sich aus den spektroskopischen Daten, speziell aus den 1H- und 13C-NMR-Werten, das Vorliegen eines Gleichgewichts zwischen den tautomeren 2-Cyanamino- und 2-Cyaniminopyrimidinformen ableiten. 3 zeichnet sich durch trichomonazide, antivirale und antimykotische Wirkung aus. Trichomonacidal Agents, II: 4,6-Disubstituted 2-(Cyanoamino)pyrimidines Carrying Branched Substituents The reaction of dicyandiamide (1) with the β-diketones 2a–b yields the 4,6-branched disubstituted 2-(cyanoamino)pyrimidines 3a–b. From spectroscopic evide…
ChemInform Abstract: FeCl3·6H2O-Catalyzed Mukaiyama-Aldol Type Reactions of Enolizable Aldehydes and Acetals.
2015
A general procedure for the title condensation of dimethylacetals derived from enolizable aldehydes with silyl enol ethers is developed using FeCl3 as the catalyst.
Dimethoxy Aromatic Compounds. VIII. Degenerate Dealkylation-Realkylation Reaction of 1-Bis(2,4-dimethoxyphenyl)-2-methylpropane.
1994
The condensation reaction under acid condition of the benzylic alcohols 1, 2 and 3 with the hexadeutero dimethoxybenzenes 4, 5 and 6 leads to the expected hexadeutero bis(dimethoxyphenyl)-2-methylpropanes 7, 8 and 9, respectively. However, the presence of both dodecadeutero and unlabelled 1-bis(2, 4-dimethoxyphenyl)-2-methylpropanes 10 and 11 indicates that 9 undergoes a rapid degenerate dealkylation-alkylation reaction.