Carboximide

Cyanopyridazines add ammonia, primary and secondary amines and hydroxylamine to give amidines or amidoximes. Substituted amides, thioamides and carboximidates can be also prepared. With hydrazine, 3-pyridazinylcarbohydrazide imide is formed and addition of methylmagnesium iodide with subsequent hydrolysis of the imine affords the corresponding pyridazinyl methyl ketone. 

Carboximide, trichloromethylthio-biocidal activity mechanism, 1, 400-401 fungicide, 1, 399 Carboximides... 

The synthesis of key intermediate 6 begins with the asymmetric synthesis of the lactol subunit, intermediate 8 (see Scheme 3). Alkylation of the sodium enolate derived from carboximide 21 with allyl iodide furnishes intermediate 26 as a crystalline solid in 82 % yield and in >99 % diastereomeric purity after recrystallization. Guided by transition state allylic strain conformational control elements5d (see Scheme 4), the action of sodium bis(trimethylsilyl)amide on 21 affords chelated (Z)-enolate 25. Chelation of the type illustrated in 25 prevents rotation about the nitrogen-carbon bond and renders... 

Carboximide 160, the C35-C42 fragment, can be traced retro-synthetically to phosphonate 169 and aldehyde 170. In the synthetic direction, the C35-C36 bond in 160 could be constructed by an intermolecular Horner-Wadsworth-Emmons (HWE)70 coupling of intermediates 169 and 170. Reduction of the unsaturated coupling product and exchange of silyl protecting groups would then furnish compound 160. 

The diastereoselectivity of the zinc iodide catalyzed reaction of the azetidinone I with the trimethylsilyl enolate derivatives of the chiral 3-(l-oxopropyI)oxazolidinones 6 was considerably lower (about 60 40), although independent generation of the zinc enolate, via exchange of the lithium enolate with zinc bromide, afforded the /9-Iactam carboximide derivatives in a ratio (RIS) 80 20177. 

Note The usual method for such conversions is via the carboximidic esters, but it has not been used of late. 

Alkenes can also be epoxidized directly with a variety of organic peroxy acids or related reagents such as peroxy carboximidic acid, RC(NH)OOH, which is readily available through an in situ reaction of... 

Cyano-l,2,4-thiadiazole-5-carboximidate 5-Imino-A3-l,2,4-thiadiazoline 3,5-Bis(diphenylamino)-l,2,4-thiadiazole... 

TABLE 4-19. Diasteroselective Hydroxylation of Chiral Carboximide Sodium Enolates Using 2-(Phenylsulfonyl)-3-Phenyl-Oxaziridine (141) in THF at — 78°C... 

This procedure demonstrates a particularly effective method for controlling the relative and absolute stereochemistry of the aldol reaction. It is quite general in scope. Alkyl-, aryl, and a,6-unsaturated aldehydes all give good results. In addition to chiral propionates, a range of related aldol reactions may be carried out. For example, the analogous aldol reactions of thioalkyl, benzyloxy, or haloacetate, as well as succinate- and crotonate-derived carboximides, have been reported. 

The dc polarography of a large group of pteridines in pH 2.0 phosphate buffer has been reported [85]. Three groups of pteridines (2,4,7-triamino-pteridines, 7-substituted-4-amino-2-aryl-5-pteridine carboxamides, and 4,7-diamino-2-aryl-5-pteridine carboximides) demonstrated polarographic reduction that was found to occur in two steps, to be pH-dependent, and to involve two electrons per step. 

Gregg et at.si) examined photosensitization of perylene pigments (Dye 15-17) on a porous Sn02 thin film instead of Ti02 film as DSC, in view of energy matching with conduction band of semiconductors and LUMO of the sensitizers. When perylene-3,4-dicarboxylic acid-9,10-(5-phenanthroline) carboximide (Dye 15) was used, Jsc of 3.26 mA-cm 2, of 0.45 V, and a photoelectric conversion efficiency of 0.89% were observed under AM 1.5 irradiation. IPCE achieves close to 40% at 460 nm. 

Carbamate, thiocar-bamate, pheny-lureas, triazines, acetanilide, uracil, propionalide, benzonitrile, benzamide, di-carboximide, dinitroaniline, pyrethroid, thiadi-azinone, metoxy-benzoic, phenol, phenoxy acid, coumarin... 

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