OXIDATION OF URAZOLES UNDER MILD AND HETEROGENEOUS CONDITIONS WITH KHSO₅ AND NaNO₂

Five‐Membered Heterocycles with Three Heteroatoms: Triazoles

“…(Table 12.17). Trichloroisocyanuric acid [274], a silica gel/sodium nitrite combination [275], an ionic complex, obtained from N 2 O 4 and 18-crown-6 [276], Oxone/ [276] Oxone/NaNO 2 /wet silica gel [277] Silica sulfuric acid/NaNO 2 [278] sodium nitrite in the presence of wet silica [277], and silica sulfuric acid/sodium nitrite [278] have all been reported as oxidants in this reaction. 1,2,4-Triazoline-3,5-dione 233 underwent an ene reaction with olefins 232 to yield trialkylated allylic urazoles 234, which were further elaborated into allylic amines 235 (Scheme 12.84) [279].…”

Synthesis and Structure of bis(cyclohexylmethyl) 3,6-bis(4-chlorophenyl)-1,2,4,5-tetrazine-1,2-dicarboxylate

“…[1][2][3][4][5][6][7][8][9][10][11] Although various reagents are capable of effecting the oxidation of urazoles, this transformation remains difficult because the initial compounds are very sensitive to the oxidant, and the preparation and purification of these compounds are problematical due to their unusual reactivity and sensitivity to reaction conditions. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Some new oxidising reagents have been prepared, and several techniques have been used. Most of them suffer at least from one of the following disadvantages: (1) high costs of preparations, (2) long reaction times, (3) hygroscopicity, (4) no selectivity, (5) photosensitivity, (6) dangerous procedures for their preparation, and (7) tedious work-up procedures.…”

Rapid and highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalysed by in situ generated I 2 using Oxone®/KI or cerium ammonium nitrate (CAN)/KI systems under mild conditions

“…In continuation of our studies using CAN 24 and Oxone R [25][26][27] in organic transformations, we have been interested in finding out a catalytic system for trimethylsilylation of alcohols and phenols. In this To find the best system for in situ generation of I 2 , first we studied a number of oxidizing agents in combination of KI for the trimethylsilylation of alcohols and phenols.…”