Freie Anthranilsaurc reagiert mit freien Imidslureestern zu Derivaten des 4-Hydroxy-chinazolins. Es wird die Darstcllung von 4-Hydroxy-chinazolyl-(2)carbonsaurenitrilen, der daraus herzustellenden Carbonsauren und von 2.2'- Polymethylcn-bis-[4-hydroxy-chinazolinen] beschrieben.Wahrend sich aliphatische a-Aminosiuren mit freien Imidstiureestem zu Amidinosauren umsetzen und hierbei nur in wenigen Fallen die Bildung von Imidazolonen beobachtet wirdz),
INTRODUCTIOK D-Tagatose is generally prepared by the isomerizatioil of D-galactose with very dilute alkali (1) or hot pyridine (4). However, the yields from these reactions are small and the isolation of the product tedious. D-Tagatose has also beell prepared by the biochemical oxidation of the rare sugar derivative D-talitol using Acetobacter suboxydans (5).We now describe a preparation of D-tagatose from D-galacturonic acid. This material is readily prepared by the enzymic hydrolysis of pectic acid (3). Isomerization of D-galacturonic acid (I) with lime water gave the calcium salt of 5-keto-L-galactonic acid (11; 2) which on treatment with an acetonesulphuric acid mixture followed by esterification with ethereal diazomethane 'Manz~script
Ersetzt man die bisher ublichen Schwefel-Amin-Gemische durch Dimorpholinodisulfid 1 und wendet dieses in einer modifizierten Willgerodt-Kindler-Reaktion auf die Ketone 2ad an, so konnen die Produkte 5, 6 und 7 isoliert werden. Die Fragmentierungsreaktion von 1, die als Konkurremreaktion bei den obengenannten Umsetzungen auftritt, fuhrt zu den Verbindungen 3 und 4. Reaction of Aryl Alkgl Ketones with Dimorpholinodisulfide. -Contribution to ihe Willgerodt- Kindler-SynthesisSubstitution of the normally used sulfur-amine mixtures by dimorpholinodisulfide 1 in a modified Willgerodt-Kindler-reaction with the ketones 2ad affords the products 5, 6 and 7.The fragmentation reaction of 1, occurring as a side reaction in the modified Willgerodt-Kindler-reaction affords the compounds 3 and 4. Die lange bekannteWillgerodt-Kindler-Reaktion2.3.4) beansprucht noch imrner reges Interesse im Hinblick auf ihren Reaktionsmechanismus. So beobachtet man z. B. bei der Umsetzung von Propiophenon mit Morpholin und Schwefel bei hoherer Temperatur zu 3-Morpholino-3-thioxo-1-phenyl-propan mehrere Reaktionsphasen5.6) : 1) W . Ochs, Diplomarbeit Univ. Frankfurt a. M. 1970.
is much more shielded. The presence of the C-phenyl group in (1) instead of the C-methyl group in (2) has the same effect, since the delocalized aromatic z-electron system of the phenyl group interacts with the vacant p-orbital of the carbene carbon, whose electron deficiency can thus be more effectively lowered than by the methyl group, which only acts inductively[31. Similarly, a dependence between degree of shielding and nature of heteroatom is observed in compounds (3), ( 4 ) , and ( 5 ) . The less electronegative nitrogen in ( 5 ) clearly confers more negative charge on the carbene carbon than does the more strongly electronegative oxygen in (3).In the case of ( 5 ) measurements were carried out on a mixture of the cis-trans isomers [41 (65:35). The isomers, which differ from each other only in the orientation of their C-and N-methyl groups, exhibit different I3C-NMR spectra. The signals for cis-and trans-(5) in the table were assigned on the basis of intensities. The I3C-NMR signals of the two isomers appear in the same sequence as do the N-methyl signals in the 'H-NMR spectrum, oiz. the signal of the cis isomer appears at higher field than that of the trans isomer. -4-phenyl-3-cyclobutene-1,2- We wish to report on the synthesis and properties of 3-mercapto-4-phenyl-3-cyclobutene-1,2-dione (PCB-SH) ( S ) , the first thio analog of the well-known PCB-OHr1I. 3-MercaptoBecause of its expected high acidity and its capability of being transformed into the novel 4-phenyl-3-thiolatocyclobutenediylium 1,2-diolate systemC2], compound ( 5 ) proves to be a very important representative of the phenylcyclobutenedione series.Dropwise addition of a benzene solution of (1) into pyridines (2) saturated with hydrogen sulfide leads to formation of the pyridinium salts ( 3 ) ['I, which have been characterized chemically and spectroscopically (see Table).In agreement with the salt structure, no peaks for the molecular ions appear in the mass spectra of (3a)-(3c). On the other hand, a peak due to the anion whose mass is increased by one unit (m/e 190) and the peak of the cation both appear with high intensity.-The absence of an IR -
L-Sorbose has been prepared f r o m 5-keto-D-gluconic acid.
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