5-Alkoxy-3-arylamino

Auch die im alkalischen Medium ablaufende Isomerisierung der 5-Alkoxy-3-arylamino-l,2,4-oxadiazole zu 5-Hydroxy-1H-1,2,4-triazolen (s. S. 517) diirfte nach anderen Mechanismen ablaufen als die nach Boulton-Katritzky aufgefiihrten Beispiele274 z.B. ... 

Sowohl die basische Hydrolyse von Dialkylamino-diaryl-dihalogen-787 als auch von Alkoxy-arylamino-diaryl-phenoxy-phosphoranen 8 liefert in meist guten Ausbeuten Phosphinsaure-amide. 

AMINO ACID DERIVATIVES, [NP(NHCH3)2]n MIXED SUBSTITUENT ARYLAMINO AND ALKOXY DERIVATIVES POLYMERIZATION OF ORCANO-HALO TRIMERS POLYMER-BOUND DYES... 

Tautomeric equilibrium between imine 18 and enamine 19 forms of 2(l//)-quinoxalinonyl acetic acid derivatives (Scheme 4) has been recognized already but found to be affected by the substituent R on the side chain. When R is hydrogen and X is alkoxy or arylamino group, both tautomers 18 and 19 exist in DMSO-r4 or CDCI3 <1994ZOR1681,... 

The two main resin linkers developed so far are shown in Scheme 18, i.e. tris(alk-oxy)benzylamide- 412 and 4-alkoxybenzylamide-type linkers)341 the former being TFA labile and thus fully compatible with Fmoc/tBu and the latter strongly acid labile and correspondingly compatible with Boc/Bzl chemistry. As shown in the case of the tris(alk-oxy)benzaldehyde handle such handles may be introduced into the C-terminal amino acid ester by reductive amination, and after suitable N -protection coupled to amino-functionalized resins (see Scheme 18). Alternatively, the tris(alkoxy)benzaldehyde-functionalized resin, BAL resin, (see Scheme 14) is used to link the C-terminal amino acid ester by reductive amination. To overcome the difficult acylation of the V -arylamino acid ester derivative on resin (best results with 10 equivalent symmetrical anhydrides), synthesis in solution of the C-terminal dipeptide building block containing the amide handle followed by its attachment to the resin has been proposed)341 ... 

Although 3-amino-l,2,4-thiadiazoles (e.g. the 5-phenyl homolog) fail to yield nitrosamines under the usual conditions,126 5-nitrosamines are well known.81, 5,190,191 Thus, 3-alkoxy-,8 3-alkylthio-,85 3-dialkyl-amino-,87 and 3-alkylsulfonyl-5-amino-86 (243) as well as 3-aryl-5-arylamino-l,2,4-thiadiazoles,74 on treatment with the calculated quantity of sodium nitrite in dilute mineral acid, or concentrated formic acid, yield crystalline nitrosamines (244). Their unusual stability has permitted a close study of their formation and properties. 170 Their positive Liebermann reaction85,87,170 and the results of their methylation (outlined in the reaction scheme) show that nitro-sation occurs in the side-chain and not in the nucleus.170... 

Die Synthesen der mit organischen Resten substituierten Phosphazene gehen in der Regel von Hexachlor-cyclotriphosphazen bzw. Octachlor-cyclotetraphosphazen aus. Durch nucleophile Substitution konnen successive alle Chlor-Atome durch Alkoxy-, Aryloxy-, Al-kylthio-, Arylthio-, Alkylamino- und Arylamino-Gruppen ersetzt werden (s. Bd. XII/2, S. 98 Iff.). 

For a recent synthesis of a-oxoacid amides from nitriles using methyl methylthiomethyl sulfoxide see ref. (478). Further interconversions between a-acylamino-a-hydroxy acid derivatives and the corresponding a-acylamino-a-aryl(alkyl)thio-, a-arylamino- and a-alkoxy compounds were reported (479, 480, 511). 

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