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【结 构 式】 
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【分子编号】65139 【品名】tert-butyl 4-[3,3-difluoro-3-(4-fluorophenyl)propyl]-1-piperidinecarboxylate 【CA登记号】 |
【 分 子 式 】C19H26F3NO2 【 分 子 量 】357.4161896 【元素组成】C 63.85% H 7.33% F 15.95% N 3.92% O 8.95% |
合成路线1
该中间体在本合成路线中的序号：(XXVIII)Addition of 4-fluorophenylmagnesium bromide (XXII) to dimethyl oxalate (XXIII) leads to methyl 4-fluorobenzoylformate (XXIV). Subsequent fluorination of (XXIV) employing diethylaminosulfur trifluoride affords the gem-difluoro ester (XXV). Reduction of ester (XXV) with NaBH4 in cold MeOH gives rise to the aldehyde hemiacetal (XXVI). Then, Wittig condensation of hemiacetal (XXVI) with the ylide generated from phosphonium salt (XXI) provides olefin (XXVII). This is partly reduced to the saturated compound (XXVIII) by treatment with in situ generated diimide, and completely reduced to (XXVIII) by catalytic hydrogenation over iridium black. Cleavage of the N-Boc protecting group of (XXVIII) to furnish piperidine (XXIX) is accomplished by means of iodotrimethylsilane in CHCl3.
| 【1】 Mills, S.G.; Kim, D.; Hale, J.; MacCoss, M.; Berk, S.; Chapman, K.; Lynch, C.; Caldwell, C.; Willoughby, C.; Rosauer, K. (Merck & Co., Inc.); Pyrrolidine modulators of chemokine receptor activity. US 6265434; WO 0059503 . |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (XXI) | 65138 | {[1-(tert-butoxycarbonyl)-4-piperidinyl]methyl}(triphenyl)phosphonium iodide | C29H35INO2P | 详情 | 详情 | |
| (XXII) | 13643 | 4-fluorophenyl magnesium bromide;Bromo(4-fluorophenyl)magnesium;bromo(p-fluorophenyl)Magnesium;p-Fluorophenylmagnesium bromide | 352-13-6 | C6H4BrFMg | 详情 | 详情 |
| (XXIII) | 37412 | methyl 2-methoxy-2-oxoacetate;dimethyl oxalate;Methyl oxalate | 553-90-2 | C4H6O4 | 详情 | 详情 |
| (XXIV) | 65143 | methyl 2-(4-fluorophenyl)-2-oxoacetate | C9H7FO3 | 详情 | 详情 | |
| (XXV) | 65141 | methyl 2,2-difluoro-2-(4-fluorophenyl)acetate | C9H7F3O2 | 详情 | 详情 | |
| (XXVI) | 65142 | 2,2-difluoro-2-(4-fluorophenyl)-1-methoxy-1-ethanol | C9H9F3O2 | 详情 | 详情 | |
| (XXVII) | 65140 | tert-butyl 4-[(E)-3,3-difluoro-3-(4-fluorophenyl)-1-propenyl]-1-piperidinecarboxylate | C19H24F3NO2 | 详情 | 详情 | |
| (XXVIII) | 65139 | tert-butyl 4-[3,3-difluoro-3-(4-fluorophenyl)propyl]-1-piperidinecarboxylate | C19H26F3NO2 | 详情 | 详情 | |
| (XXIX) | 65144 | 4-[3,3-difluoro-3-(4-fluorophenyl)propyl]piperidine | C14H18F3N | 详情 | 详情 |
合成路线2
该中间体在本合成路线中的序号：(XXVIII)The intermediate piperidine (XXIX) has been prepared by an alternative procedure. N-Boc-3-(4-Piperidinyl)propionic acid (XXX) is converted to the mixed anhydride (XXXI), which is further reacted with N,O-dimethylhydroxylamine producing the Weinreb amide (XXXII). Condensation of (XXXII) with 4-fluorophenylmagnesium bromide (XXII) leads to ketone (XXXIII). Acidic cleavage of the N-Boc group of (XXXIII), followed by treatment of the resultant piperidine (XXXIV) with benzyl chloroformate leads to the Cbz-protected analogue (XXXV). Difluorination of ketone (XXXV) is carried out by the method of Katzenellenbogen, consisting of formation of dithioketal (XXXVI), which is then reacted with 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) in the presence of HF-pyridine to afford the gem-difluoro compound (XXXVII), accompanied by an unseparable by-product. A new protecting group switch is required in order to achieve complete purification of (XXXVII), which is thus converted into the N-Boc derivative (XXVIII). Acidic cleavage of (XXVIII) as above leads to the piperidine (XXIX).
| 【1】 1,3,4-Trisubstituted pyrrolidine CCR5 receptor antagonists: Modifications of the arylpropylpiperidine side chains. Bioorg Med Chem Lett 2003, 13, 1, 119. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (XXII) | 13643 | 4-fluorophenyl magnesium bromide;Bromo(4-fluorophenyl)magnesium;bromo(p-fluorophenyl)Magnesium;p-Fluorophenylmagnesium bromide | 352-13-6 | C6H4BrFMg | 详情 | 详情 |
| (XXVIII) | 65139 | tert-butyl 4-[3,3-difluoro-3-(4-fluorophenyl)propyl]-1-piperidinecarboxylate | C19H26F3NO2 | 详情 | 详情 | |
| (XXIX) | 65144 | 4-[3,3-difluoro-3-(4-fluorophenyl)propyl]piperidine | C14H18F3N | 详情 | 详情 | |
| (XXX) | 27476 | 1-Boc-piperidin-4-ylpropionic acid; 3-[1-(tert-butoxycarbonyl)-4-piperidinyl]propionic acid | C13H23NO4 | 详情 | 详情 | |
| (XXXI) | 65145 | C18H31NO6 | 详情 | 详情 | ||
| (XXXII) | 65146 | tert-butyl 4-{3-[methoxy(methyl)amino]-3-oxopropyl}-1-piperidinecarboxylate | C15H28N2O4 | 详情 | 详情 | |
| (XXXIII) | 65147 | tert-butyl 4-[3-(4-fluorophenyl)-3-oxopropyl]-1-piperidinecarboxylate | C19H26FNO3 | 详情 | 详情 | |
| (XXXIV) | 65149 | 1-(4-fluorophenyl)-3-(4-piperidinyl)-1-propanone | 25872-68-8 | C14H18FNO | 详情 | 详情 |
| (XXXV) | 65148 | benzyl 4-[3-(4-fluorophenyl)-3-oxopropyl]-1-piperidinecarboxylate | C22H24FNO3 | 详情 | 详情 | |
| (XXXVI) | 65150 | benzyl 4-{2-[2-(4-fluorophenyl)-1,3-dithiolan-2-yl]ethyl}-1-piperidinecarboxylate | C24H28FNO2S2 | 详情 | 详情 | |
| (XXXVII) | 65151 | benzyl 4-[3,3-difluoro-3-(4-fluorophenyl)propyl]-1-piperidinecarboxylate | C22H24F3NO2 | 详情 | 详情 |