Subject phthalides

Other approaches to alkylidenecycloproparenes have been attempted without success. Aromatization of appropriate alkylidenecyclopropanes or their precursors could not be realized, and flash vacuum pyrolysis of methylene phthalide and 3-methylene-2-coumaranone afforded rearrangement products rather than alkylidenecycloproparenes via extrusion of 002. The photochemical or thermal decomposition of the sodium salt of benzocyclobutenone p-toluenesulfonyl hydrazone led to products derived from dimerization of the intermediate benzocy-clobutenylidene, or from its reaction with the solvent, but no ring-contracted products were observed. When the adduct of methylene-l,6-methano[10]annulene to dicyanoacetylene (249) was subjected to Alder-Rickert cleavage, phenylacety-lene (250) was formed, which derives reasonably from the parent 234. ... 

The coupling of 2-iodobenzoic acid and phenylacetylene under Sonogashira coupling conditions was found to give a mixture of an isocoumarin derivative and a phthalide (4.40.), The proper choice of the catalyst system led to the preferential formation of the latter compound.53 The process might also be diverted towards the formation of the isocoumarin derivative by isolation of the intermediate o-cthynyl-benzoic acid and its subjection to carefully selected cyclization conditions54... 

Aryl 2-aroylbenzothioates 51a-g (Scheme 25) were subjected to the x-ray crystal analysis and it was revealed that three thioesters 51a-c crystallized in a chiral space group, and the other crystals were racemic. Irradiation of powdered (4- )-51a at 0°C led to the production of 3-phenyl-3-(o-tolylthio)phthalide 52a as a major product (65% yield) with complete consumption of the starting material (Table 11). As expected, the asymmetric generation in 52a was observed in 30% ee. Pronounced changes in the product profiles were recognized when... 

Fluorinated bis(anhydride) 278 was used to prepare polyimide 279. Polymer 279 was used in a new copolymer formulation in which methyl methacrylate (MMA) containing dissolved polyimide was subjected to free radical polymerization. The resulting polymers were found to have improved solubility and good heat resistance. Also employed as a copolymer was poly(diphenylene phthalide) 280 <2001MI317>. 

Structural analysis of benz-phthalide synthon 85 suggested that compound 88 would be an appropriate starting point. Thus trimethoxyphthalic anhydride, readily obtained from vanillin, was subjected to reduction with sodium borohy-dride. Although both the regioisomers 89 and 90 could be formed in principle, the formation of a single isomer was observed. The correct structure, however could not be ascertained, but it really does not matter because benz-phthalides generated from both of them (Scheme 16) [86] would lead to the same target... 

In this new strategy, methyl 3,5-dihydroxybenzoate was subjected to the Gatterman reaction and the resulting product was transformed by chloro-methylation into 90 (Scheme 17), which was found to be different from the phthalide prepared earlier and therefore suggested that the correct structure for the previously prepared phthalide was 89. 

Phthalide and phenolphthalein appear to be the only lactones which have been subjected to the Schmidt reaction, and both proved to be unreactive. Acetic anhydride gives a yield of 85% of methyl amine. Phthalic anhydride yields isatoic anhydride, benzimidazolone, and an-thranilic acid. ... 

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