Synthesis of New Tetrafluorobenzo Heteroaromatic Compounds

Fluoroarenes in the synthesis of benzoannulated nitrogen-containing heterocycles

“…137 Pentafluorobenzyl bromide (316) reacts with benz imidazole 2 thione in the presence of NaH to give fused tetrafluoro derivative 317 (Scheme 92). 138 It should be noted that the cyclization pathway in this reaction differs from that in Scheme 43 and no analog of compound 133a is formed. Apparently, benzimidazole 2 thione is initially alkylated at the S atom, while in the cyclocondensation with polyfluorobenzoyl chloride 107, benzimidazole 2 thione is acylated at the N atom.…”

Fluorinated azines and benzazines containing oxygen or sulfur atoms

“…The 19 F NMR data for some condensed tetrafluoro benzothiazines are presented below (CDCl 3 , standard CFCl 3 ) [104].…”

“…The dianion generated from perimidin-2-thione by action of n-BuLi reacts with pentafluorobenzoyl chloride 96 (Y = F) to form the compound 112, a representative of the fused system of benzothiazinoperimidine [104].…”

“…The formation of fused tetrafluoro derivative 114 is described to proceed in two steps: firstly, substitution of the bromine atom of pentafluorobenzyl bromide 113 under reaction with 2-mercaptobenzimidazol leads to the intermediate 2-benzylthiobenzimidazole, which then is cyclized by treatment with NaH in THF (Scheme 43) [104].…”

Fluorine-containing pyrido[1,2-a]quinazolin-6-ones

“…The conversion of diaroyl derivatives of benzoimidazole 2 thione and imidazol idine 2 thione into imidazobenzothiazinones was de scribed earlier. 15 Alternatively, the reactions of aminopyridines 1a,b with tetrafluorobenzoyl chloride 2 could yield linear pyridoquinazolinones 7a,b.…”