[EN] TRIAZOLO-PYRIMIDINE ANALOGUES FOR TREATING DISEASES CONNECTED TO THE INHIBITON OF WERNER SYNDROME RECQ HELICASE (WRN) [FR] ANALOGUES DE TRIAZOLO-PYRIMIDINE POUR LE TRAITEMENT DE MALADIES LIÉES À L'INHIBITION DE L'HÉLICASE RECQ DU SYNDROME DE WERNER (WRN)
Homologation of Isocyanates with Lithium Carbenoids: A Straightforward Access to α-Halomethyl- and α,α-Dihalomethylamides
摘要:
Treatment of widely available isocyanates with monohalolithium and dihalolithium carbenoids provides a valuable protocol for the one-pot preparation of -halo- and ,-dihaloacetamide derivatives. While monohalolithium carbenoids can be prepared by a smooth lithium-halogen exchange, the preparation of the corresponding dihalo compounds proved to be highly dependent on the base used to realize the deprotonation, with lithium 2,2,6,6-tetramethylpiperidine emerging as optimal. The clear advantages of the procedure are: (a) broad scope of isocyanates that can be employed; (b) preservation of the optical purity when chiral materials are used; (c) divergent access to different haloamides by simply selecting the homologating agents. We also report an application of Charette's imidoyl triflate activation of a secondary amide to the synthesis of an -chloro ketone and N-15 NMR data for selected compounds.
The present invention relates to a compound of formula (I)
and salts thereof, process for preparation thereof, to compositions containing the same and to the use of such a compound in the treatment of various diseases, such as allergic rhinitis.