Pemirolast potassium, TWT-8152, DE-068, BMY-26517, TBX, Alamast, Alegysal, Pemilaston

吡嘧司特钾 吡嘧司特 Chemical Name: 9-Methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one potassium salt
CAS No. 100299-08-9, 69372-19-6 (free acid)
项目整合开发状态: Launched-1991
项目研究机构: Bristol-Myers Squibb (Originator), Mitsubishi Pharma (Licensee), Santen (Licensee)
合成路线:Two related routes for the synthesis of pemirolast potassium have been reported:1) The condensation of 2-amino-3-methylpyridine (I) with ethoxymethylenemalonodinitrile (II) gives the monocyclic intermediate (III),which is in tautomeric equilibrium with the pyridopyrimidine derivative (IV).The reaction of (IV) with aluminum azide (AlCl3.NaN3) in refluxing THF yields 4-imino-9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidine (V).Finally,this compound is first hydrolyzed with 1N HCl and then treated with KOH.2) Compound (IV) can be converted to the final product by a one-pot reaction: (VI) is treated first with NaN3 in refluxing acetic acid,then hydrolyzed with HCl and finally treated with KOH.