Nucleophilic substitution in ethyl fluorosulfonoxydifluoroacetate

Methods for the synthesis of 4 R 6,7 dihydro 1H pyrazolo[3,4 b]pyridin 6 ones (R = CF 2 SAr and 4 CFHSAr) were developed. The derivatives with R = CF 2 SAr were ob tained by both heterocyclization of 1 substituted 5 aminopyrazoles with ethyl 4,4 difluoro 3 oxo 4 phenylsulfanylbutanoate and replacement of the Br atom in 4 bromodifluoromethyl 6,7 dihydro 1H pyrazolo[3,4 b]pyridin 6 ones by sodium arenethiolates. The fragment 4 CF HSAr was introduced by replacement of the Cl atom in 4 chlorofluoromethyl 6,7 dihydro 1H pyrazolo[3,4 b]pyridin 6 ones by sodium arenethiolates. Oxidation of 4 CF 2 SPh 6,7 dihydro 1H pyrazolo[3,4 b]pyridin 6 ones gave the corresponding sulfoxides; their structures were con firmed by X ray diffraction data.Key words: pyrazolo[3,4 b]pyridines, fluorine containing 6,7 dihydro 1H pyrazolo[3,4 b] pyridin 6 ones, 1 substituted 5 aminopyrazoles, heterocyclization, fluorine containing ethyl acetoacetates, microwave irradiation, arylsulfanyl(difluoro)methyl group, arylsulfinyl(difluoro) methyl group.The pyrazolo[3,4 b]pyridine framework is a key struc tural fragment of many heterocyclic compounds showing a broad spectrum of biological activity. 1 In the last de cade, some heterocycles of this class have been found to regulate the cardiovascular system 2 and possess antiviral, 3 antitumor, 4 antiinflammatory, 5 antimicrobial, 6 and anti parasitic properties. 7 Fluoroalkyl containing pyrazolo [3,4 b]pyridines are also believed to be candidates for med ications and considered to be potential inhibitors of ade nosine deaminase and inosine 5´ monophosphate dehy drogenase. 8 Primary attention has been given to the syn thesis of CF 3 containing pyrazolo[3,4 b]pyridines 1, 9 while derivatives containing the fragment CF 2 were repre sented by CF 2 H containing pyrazolo[3,4 b]pyridines. 8 At the same time, the structural fragment CF 2 , which is ster ically similar to the CH 2 group, contrasts sharply with the latter in polarity and reactivity. 10

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“…25 The spectroscopic and physicochemical characteristics of ethyl difluoro(phenylsulfanyl)acetate are identical with the litera ture data. 26 …”

Section: H and 13 C{ H} Nmr Spectra Were Recorded On A Brukermentioning

confidence: 97%