合成路线:The Wittig condensation of 2-phenylpyrazolo[1,5-a]pyridine-3-carboxaldehyde (I) with trimethylphosphonoacetic acid methyl ester (II) by means of NaH in hot toluene gives 3(E)-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)acrylic acid methyl ester (III),which is hydrolyzed with NaOH in methanol - water yielding the corresponding free acid (IV).The reaction of (IV) with SOCl2 in DMF affords the acyl chloride (V),which is finally condensed with 2(R)-(2-hydroxyethyl)piperidine (VI) by means of bis(trimethylsilyl)acetamide and triethylamine in dichloromethane.
参考文献标题:FK-453
文献作者:Castar,J.; Prous,J.
参考来源:Drugs Fut 1992,17(11),991
合成路线:A new synthesis of FK-453 has been published:The cyclization of 1-aminopyridinium iodide (I) with 3-phenylpropynoic acid ethyl ester (II) by means of KOH in DMF gives 2-phenylpyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester (III),which is decarboxylated with 47% aqueous HBr yielding 2-phenylpyrazolo[1,5-a]pyridine (IV).The Vilsmayer formylation of (IV) with POCl3 and DMF affords 2-phenylpyrazolo[1,5-a]pyridine-3-carbaldehyde (V),which by a Horner-Emmonds condensation with 2-(diethoxyphosphoryl)acetic acid ethyl ester and NaH in THF is converted into 3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-2(E)-propenoic acid ethyl ester (VII).The hydrolysis of (VII) with NaOH in methanol gives the free acid (VIII),which by reaction with SOCl2 in dichloromethane yields the corresponding acyl chloride (IX).The condensation of (IX) with 2-(2-hydroxyethyl)piperidine (X) by means of triethylamine in dichloromethane affords FK-453 as a racemic mixture (XI),which is finally submitted to optical resolution.
参考文献标题:Discovery of FK453,a novel non-xanthine adenosine A1 receptor antagonist
文献作者:Kita,Y.; Akahane,A.; Kusunoki,T.; Terai,T.; Yoshida,K.; Shiokawa,Y.; Mitsunaga,T.; Katayama,H.
参考来源:Bioorg Med Chem Lett 1996,6(17),2059
合成路线:A new practical synthesis of FK-453,suitable for large scale manufacture is described:Bromination of cinnamic aldehyde (I) with Br2 in HOAc gives the dibromoderivative (II),which is treated with NaHSO3 and triethylamine yielding alpha-bromocinnamic aldehyde (III).The reaction of (III) with triethyl orthoformate affords the corresponding acetal (IV),which is treated with KOH in hot ethanol to give the acetylenic acetal (V).Acidic hydrolysis of the acetal (V) with sulfuric acid in refluxing water affords phenylpropargyl aldehyde (VI),which by a Horner-Emmons condensation with the phosphonate (VII) by means of KOH in DMSO gives 5-phenylpent-2(E)-en-4-ynoic acid ethyl ester (VIII).The 1,3-dipolar cycloaddition of (VIII) with 1-aminopyridinium iodide (IX) by means of KOH and K2CO3 in the same solvent yields 3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-2(E)-propenoic acid ethyl ester (X),which is hydrolyzed with NaOH in hot methanol affording the corresponding free acid (XI).Reaction of (XI) with SOCl2 and DMF gives the activated acyl chloride (XII),which is condensed with the silylated chiral piperidineethanol (XIII) [obtained by silylation of the chiral piperidineethanol (XIV) with N,N'-bis(trimethylsilyl)urea (BSU)] by means of Et3N and DMAP in CH2Cl2,yielding the silylated target compound (XV).Finally,this compound is desilylated by means of K2CO3 in methanol.
参考文献标题:Process development of a novel-xanthine adenosine A1 receptor antagonist
文献作者:Morinaga,Y.; Zanka,A.; Uematsu,R.; Yamazaki,H.; Yasuda,H.
参考来源:Org Process Res Dev 1999,3(6),389
合成路线:The Wittig condensation of 2-phenylpyrazolo[1,5-a]pyridine-3-carboxaldehyde (I) with trimethylphosphonoacetic acid methyl ester (II) by means of NaH in hot toluene gives 3(E)-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)acrylic acid methyl ester (III),which is hydrolyzed with NaOH in methanol - water yielding the corresponding free acid (IV).The reaction of (IV) with SOCl2 in DMF affords the acyl chloride (V),which is finally condensed with 2(R)-(2-hydroxyethyl)piperidine (VI) by means of bis(trimethylsilyl)acetamide and triethylamine in dichloromethane.
参考文献标题:Pyrazolopyridine cpds.and their production method
文献作者:Shiokawa,Y.; Akahane,A.; Katayama,H.; Mitsunaga,T.(Fujisawa Pharmaceutical Co.,Ltd.)
参考来源:JP 91141222
产品链接: CAS No. 121524-18-3››