121071-92-9Relevant articles and documents
A novel thiolate mediated cyclization to OPC-15161
Shinhama, Koichi,Matoba, Katsuhide,Torisawa, Yasuhiro,Minamikawa, Jun-Ichi
, p. 7427 - 7431 (2007/10/03)
An efficient synthetic route to OPC-15161 (1) was developed via novel pyrazine ring closure promoted by a lithium thiolate anion. The key intermediate (4) was prepared in a one-pot procedure by treating the methyl ester (2) with a lithium arylthiolate. This protocol does not require a free acid intermediate and thus can establish the shortest route to pyrazine dioxide skeleton from tryptophan ester derivatives. In the present transformation, lithium arylthiolates could behave like aluminium arylthiolates, and not like lithium alkylthiolates that often cleave esters to the corresponding acids. One-pot reactions that involve lengthy multiple steps in a single flask are of significant importance in contemporary organic synthesis. Utilization of a catalytic or stoichiometric promoter which can facilitate several transformations is a key to the success of such reactions. In this paper, we would like to disclose an interesting one-pot transformation discovered in our process research, which offered us novel information on the reactivity of metal thiolates. Main feature of our one-pot process is a merged deprotection-cyclization sequence. (C) 2000 Elsevier Science Ltd.
Synthesis of 2,5-Dioxygenated Pyrazine 4-Oxides: Total Synthesis of a New Inhibitor of Superoxide Anion Generation, OPC-15161
Kita, Yasuyuki,Akai, Shuji,Fujioka, Hiromichi,Tamura, Yasumitsu,Tone, Hitoshi,Taniguchi, Youichi
, p. 875 - 884 (2007/10/02)
The total synthesis of OPC-15161 1, a new inhibitor of superoxide anion generation, is described in full.Three approaches, routes A-C, have been investigated focusing on the pivotal structure 2,5-dioxygenated pyrazine 4-oxide.Among them, route A led to the total synthesis of 1.That is, the key precursor, 5-hydroxypyrazin-2(1H)-one 4-oxide 7 has been prepared from tryptophan methyl ester 2 in three steps, and direct methylation of the 5-hydroxy group of 7 or three-step methylation via the 2-O-Boc derivative 10 afforded 1 in 9.9-10.6percent overall yields.
TOTAL SYNTHESIS OF A NEW INHIBITOR OF SUPEROXIDE ANION GENERATION, OPC-15161
Kita, Yasuyuki,Akai, Shuji,Fujioka, Hiromichi,Tamura, Yasumitsu,Tone, Hitoshi,Taniguchi, Youichi
, p. 6019 - 6020 (2007/10/02)
The first total synthesis of a new inhibitor of superoxide anion generation, OPC-15161, was achieved from tryptophan methyl ester in 4-6 steps in 9.9-10.6percent overall yields.