Pyrylium salts furans, 2-acyl

Applications of di- and tri-phenylpyrylium salts continue to be exploited in the synthesis of pyridines, thiocarbonates, thiocyanates, " nitriles, and NN -diaryl-carbodi-imides. Conversion of pyrylium salts into 2-acyl-furans and 2-pyrones by sulphuric acid is dependent on the concentration of the acid. ... 

Condensation of benzo[fr]furan-3(2H)-one with 1 in acetic acid in the presence of triethylamine afforded 2-(3-benzo[fr]furyl)dimedone 481, which upon acylation with acid anhydrides in the presence of 70% perchloric acid led to the corresponding tetrahydrobenzo[t>]furo[2,3-cJ-pyrylium perchlorate 482 (94CHE283). Similarly, benzo[fr]thieno[2,3-c]-pyrylium perchlorate 484 (94CHE283) and benzo[t>]seleno[2,3-cJpyrylium salt 485 were prepared (94CHE283). 

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See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ , ]

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