Photochimie d'heterocycles azotes—V

Studies in the azole series. CIII. adamantyl and halogeno pyrazolin‐5‐ones

“…One of the most curious compounds obtained by chlorination of pyrazoles are the trispyrazoles (12)(13)(14)(15) [only three of these compounds are known, two obtained by chlorination and the third one by nitration (16)]. For instance, chlorination of pyrazole itself yields 3,5-bis-(4-chloropyrazol-l -yl)-4-chloropyrazole.…”

“…4,4-Dihalogeno derivatives [8][9][10][11][12][13] can only exist as 2-pyrazolind-ones (tautomer a) if one does not consider nonaromatic pyrazoles, such as 4,4-dihalogeno-5-hydroxyisopyrazoles. In D M s 0 -d~ pyrazolinones 1-7 exist probably as 3-pyrazolin-5-ones c. Actually, the only conclusive result is that tautomer a is not present at the limit of detection of H NMR (about 2-3%); tautomers b and c could be present in any relative proportion since their rate of interconversion is usually high in the NMR time scale.…”

The Structure ofN‐phenyl‐pyrazoles and Indazoles: Mononitro, Dinitro, and Trinitro Derivatives

“…We have published 40 papers on the title topic between 1959 and 2013; this set continues to be the only systematic study of these compounds . Our publications deal with most of these structures: 1 ; 3 ; 4 ; 5 ; 7 ; 9 ; 10 ; 11 ; 13 ; 14 ; and 15 . We have not studied compounds related to structures 2 (3‐nitro), 6 (3,5‐dinitro), 8 (2‐nitro), and 12 (2‐nitro).…”

“…We have published 40 papers on the title topic between 1959 and 2013; this set continues to be the only systematic study of these compounds . Our publications deal with most of these structures: 1 [29,31,35,36,38,44]; 3 [7,8,11,13,14,16,19,22,25,28,29,33,35,37,[39][40][41]43]; 4 [1][2][3][4][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]22,25,26,28,30,31,35,36,…”

Expedient Access to Cyanated N‐Heterocycles by Direct Flow‐Electrochemical C(sp2)−H Activation

“…[24] C(sp 2 )À H functionalization of heteroaromatics by the generation of radical cations with "green" methodologies such as electrosynthesis has recently re-emerged as a powerful cyanation tool. [25][26][27][28][29][30][31][32][33][34] The first arene electrocyanations were described by Koyama and Parker back in 1965. [35,36] In 1977, Yoshida and co-workers described the first regiospecific anodic cyanation of pyrroles and indoles using sodium cyanide.…”