AM-251, 4'-I-SR-141716A
1-(2,4-二氯苯基)-5-(4-碘苯基)-4-甲基-N-(哌啶-1-基)-1H-吡唑-3-甲酰胺Chemical Name: 1-(2,4-Dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidinyl)-1H-pyrazole-3-carboxamide
CAS No. 183232-66-8
项目整合开发状态: Preclinical
项目研究机构: Research Triangle Institute (Originator), University of Aberdeen (Originator), University of Connecticut (Originator)
合成路线:Propiophenone (IX) was condensed with diethyl oxalate to give diketone (X).Reaction with hydrazine (III) afforded pyrazole (XI).Nitration of (XI) by nitronium tetrafluoborate in acetonitrile gave a mixture of para- and ortho-nitrated compounds (XIIa-b),which were used without separation.Ester hydrolysis,followed by chlorination to (XIIIa-b) and condensation with 1-aminopiperidine (VI) gave the corresponding mixture of para- and ortho-nitro amides,which were separated by flash chromatography.The required para-isomer (XIV) was reduced by hydrazine and Raney Nickel to aniline (XV).This was finally converted to the title iodide via the reaction of the diazonium salt with NaI.
📌 参考资料/链接：
参考文献标题:Structure-activity relationships of pyrazole derivatives as cannabinoid receptor antagonists
文献作者:Lan,R.; Liu,Q.; Fan,P.; Lin,S.; Fernando,S.R.; McCallion,D.; Pertwee,R.; Makriyannis,A.
参考来源:J Med Chem 1999,42(4),769
📄 详细内容
合成路线:Claisen condensation of 4'-bromopropiophenone (I) with diethyl oxalate using lithium bis(trimethylsilyl)amide provided the lithium salt of diketone (II).Subsequent condensation of (III) with 2,4-dichlorophenyl hydrazine (III),followed by cyclization of the intermediate hydrazone in refluxing AcOH yielded the desired pyrazole (IV).After hydrolysis of the ester group of (IV),the resulting carboxylic acid was converted to acid chloride (V) by treatment with SOCl2.Coupling of (V) with 1-aminopiperidine (VI) gave amide (VII).Conversion of (VII) to the tributyl-stannyl derivative (VIII) was achieved by reaction with hexabutylditin in the presence of catalytic tetrakis(triphenylphosphine)palladium.The desired iodo compound was then obtained by treatment of (VIII) with NaI and chloramine-T.
参考文献标题:Preparation of iodine-123 labeled AM251: A potential SPECT radioligand for the brain cannabinoid CB1 receptor
文献作者:Lan,R.; et al.
参考来源:J Label Compd Radiopharm 1996,38(10),875
产品链接: CAS No. 183232-66-8››