Phthalimide Subject

Systematic studies of the photoreactions of cyclic imides and in particular of phthalimide derivatives have been the subject of a review.278 One of the... 

The simplicity of the two-phase modification of the Gabriel synthesis of primary amines, via the N-alkylation of potassium phthalimide, makes the procedure considerably more convenient than the traditional method, which normally requires the use of anhydrous dipolar aprolic solvents. The reaction can be conducted under solid liquid conditions using potassium hydroxide in toluene [25], or with preformed potassium phthalimide [26, 27] (cf ref. 28). As is normal for acylation reactions, relatively mild conditions are required for the preparation of the A-ethoxycarbonyl derivative [29], whereas a reaction temperature of 100°C is generally used for N-alkylation (Table 5.16). The reaction time for the soliddiquid two-phase system can be reduced dramatically with retention of the high yields, when the reaction mixture is subjected to microwave irradiation [30]. 

The photoaddition of phthalimides and related dicarbox-imides to alkenes has been the subject of detailed study over the years. In the presence of added methanol, the photoreactions of dicarboximides with alkenes also result in the formation of methanol-incorporated products. The efficiency of alcohol trapping by the N-methylphthalimide-alkene radical ion pair, which is involved in... 

The reactions involving alkoxyphosphonium salts are also efiective for the A(-alkylation of phthalimide with virtually complete inversion of the secondary methanol center. Thus, the reaction of (S)-alcohol (81) with phthalimide, DEAD and triphenylphosphine afforded (82), which was subjected to a sequence of reactions to yield (2/ ,5f )-diamine (83) and the (2/ ,5Sj-isomer in a ratio of 99.4 0.6. The secondary... 

As can be seen from the foregoing, phthalimide photocyclizations have provided useful synthetic routes to a variety of heterocyclic products. Machida et al. have used the reaction to yield the spiro compounds (325) from the irradiation (in methanol) of the phthalimide derivatives (326). The products are presumed to be formed via bond formation in the biradical produced by the addition of methanol to the radical cation/r ulical anion pair. The indoles (327) undergo photochemical (2-f-2)-addition with A methyl phthalimide to afford the oxetan adducts (328). This work has also been the subject of a patent application. " ... 

Mediators essential for laccase bleaching of pulp have been the subject of coupled experimental and computational research by Sealy et al. [55]. This study examined the effect of substitution on N-hydroxybenzotriazole, and the activity of phthalim-ides. N-hydroxybenzotriazole itself was more effective in lowering kappa numbers than any of the derivatives that were tested. Computationally, the bond dissociation energy was generally lower for N-hydroxybenzotriazole than the derivatives. Similarly, the most active of the phthalimide mediators had the lowest bond dissociation energy. 

In 1928, at Grangemouth, Scotland, at the works of Messrs. Scottish Dyes Ltd., traces of a dark blue insoluble complex were noticed in the iron vessels used to prepare phthalimide from phthalic anhydride and ammonia (65, 221). This product was subsequently shown to be ferrous phthalo-cyanine. Since then literally thousands of patents and publications concerning the phthalocyanines have appeared. It is probable that the phthalocyanines have been the subject of more physical studies than any other single class of compound, partly as a result of their unique structure and partly because of their high thermal and chemical stability. 

Base modification at the 4-position of pyrimidines leads to loss of base-pairing properties. The thiol moiety in 91 was deprotected after ODN synthesis using 1 M DBU in acetonitrile. The modified oligothymidylate was then cleaved from the solid phase and reacted with N-(2-chloroethylthio)phthalimide to yield 92, which was subjected to further derivatization [264]. Purine base positions accessible for ligand attachment are C-8 of adenosine (93) [265] and C-2 of guanosine (94) [266]. 

The last example presented in this section also involved a specialized hydrazone intermediate, a N-phlhalimide hydrazone. Once the amine group in 1,114 (prepared by literature methods) was blocked as the phthalimide, the acid moiety in 1.114 was subjected to the Amdt-Eistert sequence shown. This reaction sequence extended the carbon chain by one and this new acid was converted to its t-butyl ester (7.775).65 The N-phthalimido protecting group was removed, with reduction of the imine moiety, to give 5-methyl-7-aminooctanoic acid, 1.116. When another... 

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