合成路线:1) The esterification of 1-(4-chlorobenzoyl)-3-(4-phenyl-1-piperazinyl)propanol (I) with phosgene by means of triethylamine in CHCl3 gives the corresponding chloroformate ester (II),which is then cyclized by heating.
合成路线:2) By direct cyclization of (I) with N,N'- carbonyldiimidazole (III) in refluxing benzene.
合成路线:3) By direct cyclization of (I) with phosgene in refluxing CHCl3.
合成路线:Cyanoacetic acid (I) is condensed with urethane (II) in hot Ac2O to afford N ethoxycarbonyl-cyanoacetamide (III).Subsequent reaction of (III) with triethyl orthoformate yields alpha-cyano-beta-ethoxy-N-ethoxycarbonyl-acrylamide (IV).The ethoxy group of (IV) is then displaced with hydrazine hydrate in EtOH to produce the hydrazino acrylamide (V).Finally,thermal cyclization of (V) gives rise to the title pyrazolopyrimidine (1,2).
参考文献标题:Process for the preparation of biologically active cpds.as well as novel cpds.
文献作者:Shaw,G.; Baildon,S.; Lees,P.Sr.
参考来源:DE 1814082
合成路线:In an alternative method,chlorination of pyrazole-3,4-dicarboxylic acid (I) with SOCl2 produces acid chloride (II),which is further converted into diamide (III) upon treatment with ammonia.Subsequent Hofmann rearrangement of amide (III) in the presence of sodium hypochlorite leads to the target pyrazolopyrimidine compound (3,4).
参考文献标题:Pyrazolo-(3,4-d) pyrimidines
文献作者:Hitchings,G.H.; Faco,E.A.(GlaxoSmithKline Inc.)
参考来源:US 3474098
合成路线:Cyanoacetic acid (I) is condensed with urethane (II) in hot Ac2O to afford N ethoxycarbonyl-cyanoacetamide (III).Subsequent reaction of (III) with triethyl orthoformate yields alpha-cyano-beta-ethoxy-N-ethoxycarbonyl-acrylamide (IV).The ethoxy group of (IV) is then displaced with hydrazine hydrate in EtOH to produce the hydrazino acrylamide (V).Finally,thermal cyclization of (V) gives rise to the title pyrazolopyrimidine (1,2).
参考文献标题:Purines,pyrimidines,and imidazoles.Part XXXVII.Some new syntheses of pyrazolo[3,4-d]pyrimidines,including allopurinol
文献作者:Hildick,B.G.; Shaw,G.
参考来源:J Chem Soc 1971,(9),1610
产品链接: CAS No. 2465-59-0››