Reissert compounds arylation

The Reissert compound (5.7 mmol), an aryl aldehyde and TEBA-C1 (14 mg, 0.06 mmol) in CH,C1, (3 ml) are sonicated with aqueous NaOH (50%, 2.5 ml) for 5 min. EtOH (8 ml) and CH,C1, (15 ml) are added and sonication is continued for a further 85 min and the mixture is then poured into H,0 (20 ml). The aqueous phase is separated and extracted with CH2C1, (3x10 ml). The combined organic solutions are dried (MgS04), concentrated to 20 ml, and saturated with HCI gas to yield the hydroxymethylheteroarene hydrochloride (80-99% ). 

Reissert compounds (cf Section 3.2.1.6.8.iv) can be deprotonated (NaH/HCONMe2) to give anions (e.g. 507) which react with electrophiles to give intermediates (508) which can be hydrolyzed to substituted heterocycles (509). Electrophiles utilized include alkyl and reactive aryl halides and carbonyl compounds. 

Reissert compounds (l-acyl-l,2-dihydro-2-quinolinecarbonitriles) have been prepared on cross-linked polystyrene and C-alkylated in the presence of strong bases (Entry 8, Table 15.25). Treatment of polystyrene-bound C-alkylated Reissert compounds with KOH leads to the release of isoquinolines into solution (Entry 9, Table 15.25). The reaction of support-bound quinoline- and isoquinoline /Y-oxides with acy-lating agents followed by treatment with electron-rich heteroarenes and enamines has been used to prepare alkylated and arylated derivatives of these heterocycles (Entry 10, Table 15.25 see also Table 15.26). 

Treatment of the isoquinoline Reissert compound (2) with sodium hydride in dimethylformamide, with 50% aqueous sodium hydroxide-TEBA chloride, or with 50% aqueous sodium hydroxide-TBA chloride and an activated aryl halide, such as 2,4-dinitrofluorobenzene, 2-bromo-3-nitropyridine, 4-nitrochlorobenzene, t-butyl 2-chloro-5-nitrobenzoate, ... 

Monographs on Contemporary Heterocyclic Chemistry and quinoline chemistry have appeared. The latter work contains reviews on alkyl- and aryl-quinolines, Reissert compounds and related dihydroquinolines, and quinoline N-oxides. The chemistry of quinolizines, 0 1, 7-naphtliyridines, azaphenalenes, 2... 

Stamegna and McEwen noted the presence of minor products such as a-benzamidostilbenes from the Stevens rearrangement of analogs of Reissert compounds. These minor products could be formed by recombination of radicals formed by homolysis. Further evidence for this was provided in that the minor products were observed for radical intermediates one would predict to be relatively stable (such as benzyl radicals), yet they were not observed if the radical intermediate was not expected to be stable (such as aryl radicals). 

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