Acylamino groups

In the olivanic acid series of carbapenems the ( )-acetamidoethenyl grouping can be isomerised to the (Z)-isomer (19) (22) and reaction with hypobromous acid provides a bromohydrin that fragments to give a thiol of type (20) when R = H, SO H, or COCH. The thiol is not isolated but can react to provide new alkyl or alkenyl C-2 substituents (28). In the case of the nonsulfated olivanic acids, inversion of the stereochemistry at the 8(3)-hydroxyl group by way of a Mitsunobu reaction affords an entry to the 8(R)-thienamycin series (29). An alternative method for introducing new sulfur substituents makes use of a displacement reaction of a carbapenem (3)-oxide with a thiol (30). Microbial deacylation of the acylamino group in PS-5 (5) has... 

Alkoxy-6-chloropyridazine is oxidized at the nitrogen next to the chlorine. On the other hand, IV-oxidation of compounds with an amino or acylamino group and either an alkoxy group or a chlorine atom at positions 3 and 6 always takes place at the nitrogen next to the amino group. 

In their acidity, basicity, and the directive influence exerted on electrophilic substitution reactions in benzenoid nuclei, acylamino groups show properties which are intermediate between those of free amino and hydroxyl groups, and, therefore, it is at first surprising to find that the tautomeric behavior of acylaminopyridines closely resembles that of the aminopyridines instead of being intermediate between that of the amino- and hydroxy-pyridines. The basicities of the acylaminopyridines are, indeed, closer to those of the methoxy-pyridines than to those of the aminopyridines, the position of the tautomeric equilibrium being determined by the fact that the acyl-iminopyridones are strong bases like the iminopyridones and unlike the pyridones themselves. Thus, relative to the conversion of an... 

Some substituents such as the acylamino group are readily decomposed by many nucleophiles to give a poorer leaving group (e.g., amino). Others, such as nitroamino and sulfonylamino, are less reactive when they are anionized by the nucleophile. 3-Nitroamino-pyridazine (117) and its 6-methyl derivative are readily aminated with benzylamine (130°, short time ). 4,6-Dimethyl- and 6-methyl-2-nitroaminopyrimidine undergo 2-substitution on warming a few minutes with hydroxylamine, hydrazine, primary or secondary alkylamines, or anilines. 

The following structures will show that macrocyclic rings between metal ions or BR2 units and acyloxy or acylamino groups have some relationship with rigid coronands [Ic]. 

Addition of an acyl group and an acylamino group to a double bond... 

The simplest monoazo dyes fail to meet these requirements, but by choosing intermediates known to confer substantivity and by building up the molecule to provide the necessary length and coplanarity (section 3.2.1), direct dyes can be produced from this class. Thus the highly substantive character of the benzothiazole nucleus is exploited in Cl Direct Yellow 8 (4-58), as is the alignment of the azo, ureido and acylamino groups in the substituted J acid coupling component of Cl Direct Red 65 (4-59). 

The list of suitable substituents includes acylamino groups, but especially halogen atoms such as chlorine or bromine. Halogenated derivatives are obtained from tetrahalogen phthalic anhydride or naphthalene-2,3-dicarboxylic anhydride, by... 

A substituted acylamino group can be introduced by reaction of pyridazine 1-oxide with jV-phenylbenzonitrilium hexachloroantimonate 3-JV-benzoylanilinopyridazine is formed (75JOC41). 

The thiol group can also be found in heterocyclic compounds such as 2-mercaptobenzothiazole (9) and echinoclathrine C (10). Compound 9 was isolated from the symbiont bacterium Micrococcus sp., which was obtained from the sponge Tedania ignis [13]. The pyridine alkaloid echinoclathrine C (10) and its S-acetylated derivative, echinoclathrine B (11), were isolated from the Okinawan sponge Echinoclathria sp. [14]. The position of the hydroxyl and acylamino group on the phenyl ring in echinoclathrines (11 and 10) was recently corrected [15]. Compound 11 showed weak immunosuppressive activity in the mixed lymphocyte reaction assay with an IC50 of 9.7 pg/ml [14]. 

Acylamino groups also are useful activating groups and have the advantage that the amino groups obtained after hydrolysis of the acyl function can be removed from an aromatic ring by reduction of the corresponding diazonium salt with hypophosphorous acid, preferably in the presence of copper(I) ions. 

Electron impact MS of open-chain monomeric derivatives was useful for both determination of the position of acylamino groups and linkage analysis. The mass spectrum of the carbonyl-reduced and methylated derivative of the monosaccharide 48 from P. aeruginosa 07a,7d (Fig. 12) showed the expected fragmentation pattern, which demonstrated the... 

Compounds with Reactive Methylene Groups. In this group the coupling components with the greatest industrial importance are the A-acetoacetyl derivatives of aromatic amines (acetoacetarylides) CH3COCH2CONHAr. Anilines substituted by halogen, alkyl, alkoxy, nitro, and acylamino groups are most suitable (e.g., Napthol AS-IRG). 

The Morgan-Walls cyclization has also been employed in eases where the acylamino group is attached to a reduced ring. For example, the amides (13a-c,41 and d42) are readily cyclized by phosphoryl chloride and the tetrahydro-l,2-benzophenanthridine (14) has been prepared... 

Fig. 14 Indole derivatives, with changes in the 5-methoxy and acylamino groups [134]...

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