phosphoranyl radical chemistry allows for precise cleavage of a stronger C-O bond and formation of a weaker C-Cbond by 1,5-aryl migration under mild reaction conditions. This new protocol is independent of substrate redox-potential, electronic, and substituent effects. It affords a general and promising access to 60 examples of synthetically versatile o-amino and o-hydroxy diaryl ketones under redox-neutral
[EN] A PROCESS FOR PREPARING BENZO[B]THIOPHENE DERIVATIVES<br/>[FR] PROCÉDÉ DE PRÉPARATION DE DÉRIVÉS DE BENZO(B)THIOPHÈNE
申请人:HEXAL AG
公开号:WO2011047877A1
公开(公告)日:2011-04-28
The present invention relates in general to the field of organic chemistry, and in particular to the preparation of benzo[b]thiophene derivatives. These benzo[b]thiophene derivatives are useful as intermediates in the synthesis of pharmaceutically active agents such as raloxifene or derivatives thereof.
High thermal stabilities are achievable in linear or multidimensional sulfone, solvent resistant oligomers by incorporated oxazole, thiazole, or imidazole linkages into the oligomer backbone. Blended oligomers of crosslinking oligomers and noncrosslinking compatible polymers are also described. The oligomers include residues of four-functional compounds of the formula:
(or isomers thereof) wherein M = -CO-, -S-, -0-, -SO2- or -(CF3)2C-; and Y = -OH, -SH, or -NH2.
In an improved method, the reactants are condensed at .or below ambient temperature in the presence of pyridine in a suitable solvent such as N,N'-dimethylacetamide (DMAC).