Phthalimides reduction

Treatment with PCI5 gives phthalyl chloride reduction with zinc and ethanoic acid or NaOH gives phthalide. Fusion with urea gives phthalimide. 

Electrolytic reduction of phthalimide and of phthalimidines which are at an oxidation level above that of isoindole, proceeds through the isoindole to the isoindoline stage, which is then stable to further... 

An isoindol1 none moiety forms part of the aromatic moiety of yet another antiinflammatory propionic acid derivative. Carboxylation of the anion from -nitro-ethylbenzene (45) leads directly to the propionic acid (46). Reduction of the nitro group followed by condensation of the resulting aniline (47) with phthalic anhydride affords the corresponding phthalimide (48). Treatment of that intermediate with zinc in acetic acid interestingly results in reduction of only one of the carbonyl groups to afford the isoindolone. There is thus obtained indoprofen (49). ... 

One disadvantage of the ARO reactions with azide, p-anisidine, and phthalimide described above is that each product requires further manipulation (reduction,... 

Figure 4, Highest area sample NMOR levels in a tire factory, showing the reduction achieved. The October 1979 reduction was attributed to venting, the December 1979 reduction to the installation of exhaust canopies, and the February 1980 reduction to use of a phthalimide derivative instead of diphenylnitrosamine...

A similar sequence that takes place under milder conditions uses 4-nitrophthalimides as the protecting group and /V-melhylhydrazine for deprotection.234 Reduction by NaBH4 in aqueous ethanol is an alternative method for deprotection of phthalimides. This reaction involves formation of an o-hydroxybenzamide in the reduction step. Intramolecular displacement of the amino group follows.235... 

Esters of (V-hydroxyphthalimide can also be used for decarboxylation. Photolysis in the presence of an electron donor and a hydrogen atom donor leads to decarboxylation. Carboxyl radicals are formed by one-electron reduction of the phthalimide ring. 

A useful approach for the preparation of chiral (3-aminophospho-nic acids from the naturally occurring a-amino acids has been reported.139 The overall scheme (Equation 3.4) involves formation of the phthalimide-acid halide from the starting a-amino acid followed by a Michaelis-Arbuzov reaction with triethyl phosphite to give the acylphosphonate. Complete reduction of the carbonyl group in three steps followed by hydrolysis of the ester and amide linkages provides the target material in very high yield without racemization (>99% ee). 

Phthalic anhydride initially reacts with ammonia, which in turn is liberated, for instance, by decomposition of urea. Diiminophthalimide is then produced via phthalimide and monoiminophthalimide. Subsequent self-condensation (as in the phthalonitrile process) under cleavage of ammonia affords polyisoindolenines, which form complexes with copper ions. Ring closure is achieved through further release of ammonia, and copper phthalocyanine is finally obtained by reduction. 

Results of reductions of cyclic anhydrides to lactones with sodium amalgam or with zinc are inferior to those achieved by complex hydrides [1020]. However, 95.6% yield of phthalide was obtained by reduction of phthalimide with zinc in sodium hydroxide [1021]. 

Phthalimide was hydrogenated catalytically at 60-80° over palladium on barium sulfate in acetic acid containing an equimolar quantity of sulfuric or perchloric acid to phthalimidine [7729]. The same compound was produced in 76-80% yield by hydrogenation over nickel at 200° and 200-250 atm [43 and in 75% yield over copper chromite at 250° and 190 atm [7730]. Reduction with lithium aluminum hydride, on the other hand, reduced both carbonyls and gave isoindoline (yield 5%) [7730], also obtained by electroreduction on a lead cathode in sulfuric acid (yield 72%) [7730]. 

Carboxyl radicals are formed from one-electron reduction of the phthalimide ring. 

Another method by mercuration starts with keto alcohol 207 (390). The amino alcohol (208) obtained from 207 by reductive amination was protected by a standard procedure to afford the phthalimide (209). Successive treatment of 209... 

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