Phthalimide, A

The observed catalytic effect of the crown ether appears to be dependent on the nucleophile employed in both polymerization and corresponding model reactions. Not surprisingly, it appears that the stronger the nucleophile employed, the smaller the catalytic influence of the crown ether. For example, with potassium thiophen-oxide yields of polymer or model products were almost quantitative with or without catalyst. By contrast, the reaction of PFB with potassium phthalimide, a considerably weaker nucleophile, affords 6 in 50% with catalyst and in 2-3% without catalyst under identical conditions. However, it may be that this qualitative difference in rates is, in fact, an artifact of different solubilities of the crown complexed nucleophiles in the organic liquid phase. A careful kinetic study of nucleophilicity in catalyzed versus non-catalyzed reactions study is presently underway. 

To discern the ion-radical nature of reactions, the so-called intramolecular and intermolecular proton/deuterium isotope effects may be of use. Baciocchi et al. (2005) revealed ion-radical mechanism for A-demethylation of A,A-dimethylanilines, (CH3)2NAr, by phthalimide-A-oxyl radical (Scheme 4.14). In this reaction, ( e/ D)intra values were derived for reactivity of (CD3)(CH3)NAr, whereas ( H/ D)inter was referred for the reactivity of (CD3)2NAr. The values of (A e/ D)intra were found to be always different and higher than These results, although are incompat-... 

This paper traces in some detail the path which led to the discovery of a new class of herbicides, the 2-(5-oxo-2-imidazolin-2-yl)arylcarboxylates. The journey started when it was found that a phthalimide, a-isopropyl-a-methyl-l,3-dioxo-2-isoindoline-acetamide, had sufficient herbicidal activity to warrant further synthesis effort. This work led to a series of analogs essentially devoid of herbicidal activity yet possessing interesting plant growth regulating effects. Further chemical modifications resulted in the synthesis of two new groups of compounds, imidazoisoindolediones and dihydro-imidazoisoindolediones, and the return of herbicidal activity. The imidazoisoindolediones were in turn transformed into o-(5-oxo-imidazo-lin-2-yl)benzoates, the first members of a very interesting new class of herbicides. 

Thiiranes can be formed directly and stereospecifically from 1,2-disubstituted alkenes by addition of trimethylsilylsulfenyl bromide, formed at -78 C from reaction of bromine with bis(trimethylsilyl) sulfide (Scheme 7).12 A two-step synthesis of thiiranes can be achieved by addition of succinimide-A/-sulfe-nyl chloride or phthalimide-A -sulfenyl chloride to alkenes followed by lithium aluminum hydride cleavage of the adducts (Scheme 8).13 Thiaheterocycles can also be formed by intramolecular electrophilic addition of sulfenyl chlorides to alkenes, e.g. as seen in Schemes 914 and 10.13 Related examples involving sulfur dichloride are shown in Schemes 1116 and 12.17 In the former case addition of sulfur dichloride to 1,5-cyclooctadiene affords a bicyclic dichloro sulfide via regio- and stereo-specific intramolecular addition of an intermediate sulfenyl chloride. Removal of chlorine by lithium aluminum hydride reduction affords 9-thiabicyclo[3.3.1]nonane, which can be further transformed into bicyclo[3.3.0]oct-1,5-ene.16... 

The Gabriel-malonic ester synthesis uses an aminomalonic ester with the amino group protected as a phthalimide. A variation has the amino group protected as an acetami-do group. Propose how you might use an acetamidomalonic ester synthesis to make phenylalanine. 

N 0 Me 0 From hydroxymethyl polystyrene by treatment with COClj, HjNNHCOjMe and NBS or Cl,.2i Mitsunobu reactions esters from carboxylic acids and alcohols lactones from hydroxy acids A/-aUcylation of phthalimides, a-alkylation of cyanoacetate carbodiimides from thioureas. ... 

A mixture of phthalimide, a-bromoacetophenone, NaB02-4H20, KBr, and a little BU4NI in DMF stirred at ca. 20° for 10 h N-phenacylphthalimide. Y 82%. In contrast to the standard Gabriel synthesis (with K-phthalimide), the method described here is performed on the free imide under mild conditions. F.e. inch succinimide derivs. s. S.I. Zavyalov et al., Izv. Akad. Nauk SSSR Ser. Khim. 1988, 1940. 

Aniino-2,3,6-trideoxy-i/ireo-hexopyranos-4-ulose D-form Me glycoside, iV-phthalimide, A-457... 

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