Naphthalic anhydride formation

Excessive activity of the enzyme aldose reductase sometimes accompanies diabetes. The net result is often accumulation of reduced sugars such as galactose in the lens of the eye and ensuing cataract formation. A1 restatin (43), an aldose reductase inhibitor, is one of the first agents found that holds promise of preventing diabetes-induced cataracts. The compound, actually used as its sodium salt, is prepared in straightforward manner by imide formation between 1,8-naphthalic anhydride (41) and glycine. ... 

Acenaphthene. The catalytic vapor phase oxidation of ace-naphthene results in the formation of a variety of products such as acenaphthylene, aceuaplithoquinone, naphthaldehydic add, naphthalic anhydride, maldc acid, etc.48 Catalysts similar to those used in the oxidation of anthracene... 

Novel bis(naphthalic anhydrides) containing bridging groupings and/or bulky substituents are reviewed. Reactions of these compounds with aromatic diamines and bis(o-phenylene diamines) led to the formation of polynaphthylimides and polynaphthoylenebenzimidazoles combining solubility in organic solvents with high thermal, heat and chemical resistance. 

But it should be noted that the majority of polyheteroarylenes based on bis(naphthalic anhydrides) are systems displaying low processability of products The final polyheteroarylenes are infusible and soluble only in strong adds (sulfuric, methylsulfuric, polyphosphoric) [59-71] and the reactions involving bis(naphthalic anhydrides) are difficult to carry out as stepwise processes due to a reduced electrophilic reactivity of the anhydrides [39, 72-74] and the easy formation of six-membered naphthalimide systems. 

Another way of rendering PNI soluble is to use various bis(naphthalic anhydrides) of less condensed structure when compared with DPTA and DNTA [19, 21, 27, 69-82]. Interaction of bis(naphthalic anhydride) with 1,12-diaminododecane (Scheme 1.15) leads to the formation of PNI very soluble in methylene chloride and chloroform [69]. 

The hydrolysis and interconvertability of 2,3-iV-butyl-naphthalimide (2,3-NBN) (54) and 2,3-A -butyl-naphthalamide (2,3-NBaniide) (55) and of their corresponding isomers, 1,8-A -butyl-naphthalimide (1,8-NBN) (56) and 1,8-A -butyl-naphthalamide (1,8-NBamide) (57) (Scheme 19), were investigated experimentally over a wide pH range and theoretically, in the gas phase, by ab initio quantum methods. In mild alkali, 1,8-NBN (56) equilibrates with 1,8-NBamide (57) but 2,3-NBN (54) yields 2,3-NBamide (55) quantitatively. The former observation was attributed to the reluctance of the initially formed tetrahedral intermediate (58) to proceed to the amide unless it suffered further attack by HO to form the dianion (59). In acid, the formation of 1,8-naphthalic anhydride (60) from 1,8-NBamide (57) was demonstrated, but none of the 1,2-naphthalic anhydride was formed from 1,2-NBamide (55). The rate of... 

Interaction of this diamine with two-fold molar amount of naphthalic anhydride and equimolar amount of naphthalene-1,4,5,8-tetracarboxylic add dianhydride led to the formation of bis (model) compound and poly-naphthylimide-containing phosphonic add groups, respectively (Scheme 7). 

Later, Barbas et al. performed irradiation X > 350 nm) of ACN on a dry sihca gel-air interface with monolayer coverage of 0.3 9%. The dimers 1 were produced along with oxidation products of ACN. These products included 1,2-acenaphthenedione, 2-hydroxy-1-acenaphthenone, 1,8-naphthalenedicar-boxaldehyde, and 1,8-naphthalic anhydride. For formation of 1, results derived by Barbas et al. support the validity of de Mayo s results. Thus, the yield of cisoid-l increased much more dramatically than that of transoid-l and rose from 2.4 to 13.2 as the surface coverage was increased from 0.3 to 8.6%, which indicates that the contribution from the Sj state to cisoid-l formation is more signifrcant than that from the Ti state. 

On reaction with zinc dust in alkaline medium, naphthalic acid is subjected to reductive dimerization with so-called deoxynaphthalic anhydride 366 as the result (13CB1484). The formation of diarylnaphthalides 371 on... 

These data reveal a logical pathway to a possible enhancement in thermal and chemical stability of polyheteroarylenes, Le. in the above mentioned reactions a replacement of bis(phthalic anhydrides) by bi naphthalic) ones the structure of which would determine the formation of systems containing six-membered imide rings - either isolated ones or those condensed with other heterocyclic moieties. 

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