906474-56-4

Upstream product

• 136285-65-9 ethyl 2-[(N-tert-butoxycarbonyl)amino]-3-nitrobenzoate 
• 124750-51-2 N-(triephenylmethyl)-5-<4'-(bromomethyl)-biphenyl-2-yl>tetrazole 

Downstream Products

• 1073117-27-7 2-[(N-tert-butoxycarbonyl)-[[2'-[1-(triphenylmethyl)-1H-tetrazol-5-yl]biphenyl-4-yl]methyl]amino]-3-nitrobenzoic acid 
• 145040-37-5 candesartan cilexetil 
• 1073117-28-8 (+/-)-1-[[(cyclohexyloxy)carbonyl]oxy]ethyl 2-[(N-tert-butoxycarbonyl)-[[2'-[1-(triphenylmethyl)-1H-tetrazol-5-yl]biphenyl-4-yl]methyl]amino]-3-nitrobenzoate 

Relevant academic research and scientific papers

A NEW PROCESS FOR THE PREPARATION OF CANDESARTAN CILEXETIL

The present invention discloses the process for the preparation of candesartan cilexetil comprising the steps of hydrogenation of N02group of 1-(((cyclohexyloxy)carbonyl)oxy)ethyl 2-((tert-butoxycarbonyl)((2'-(1-tntyl-1H-tetrazol-5-yl)-[1,1'-biphenyl]-4-yl)methyl)amino)-3-nitrobenzoate by using a catalyst in an organic solvent, subsequent cleavage of the N-Boc group under acidic condition, followed by isolation of solid 1-(((cyclohexyloxy)carbonyl) oxy)ethyl 2-(((2'-(l H-tetrazol-5-yl)-[1,1'-bipheny|]-4-yl)methyl)amino)-3-aminobenzoate in the form of any pharmaceutically acceptable salt and ring closure by using tetraethyl orthocarbonate in an organic solvent to obtain the final product candesartan cilexetil.

Novel and practical synthesis of candesartan cilexetil

A novel and convergent synthetic route of candesartan cilexetil (API of Atacand), an effective angiotensin II receptor blocker, is described. Cleavage of the N-Boc and N-trityl protective group are implemented simultaneously and formation of the benzimidazole ring is conducted at the last step of this route, which gives candesartan cilexetil in 55% yield over six steps with 99.1% purity (HPLC).