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【结 构 式】 
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【分子编号】20678 【品名】ethyl 3-(1,3-benzodioxol-5-yl)-5-(4-methoxyphenyl)-3,4-dihydro-2H-pyrrole-4-carboxylate 【CA登记号】 |
【 分 子 式 】C21H21NO5 【 分 子 量 】367.40148 【元素组成】C 68.65% H 5.76% N 3.81% O 21.77% |
合成路线1
该中间体在本合成路线中的序号：(IV)The Michael reaction between 3,4-(methylenedioxy)-beta-nitrostyrene (I) and ethyl (4-methoxybenzoyl)acetate (II) in the presence of DBU gave adduct (III) as a mixture of isomers. Hydrogenation of this nitro ketone over Raney-Ni afforded, after spontaneous cyclization of the resulting amino ketone, the pyrroline (IV). Further reduction of the imine with NaBH3CN yielded a mixture of three pyrrolidine isomers. The desired trans-trans isomer (VI) could not be separated from the cis-trans isomer by column chromatography. However, the pure cis-cis compound (V) was isomerized to (VI) with NaOEt in refluxing EtOH. The protection of the amine as the tert-butyl carbamate with Boc2O, and saponification of the ester function provided the racemic acid (VII). Resolution of (VII) was achieved by conversion to the mixed anhydride (VIII) with pivaloyl chloride, followed by condensation with the lithium salt of (S)-4-benzyl-2-oxazolidinone (IX), and chromatographic separation of the resulting diastereomeric imides. Alternatively, racemic (VII) could be resolved by crystallization of its salt with (R)-a-methylbenzylamine. Removal of the Boc group from the appropriate isomer (X) with HCl in dioxan, followed by alkylation with N,N-dibutylbromoacetamide (XI) in the presence of i-Pr2NEt furnished the pyrrolidinylacetamide (XII). Finally, hydrolysis of the imide with lithium hydroperoxide provided the target acid.
| 【1】 Winn, M.; et al.; 2,4-Diarylpyrrolidine-3-carboxylic acids-potent ETA selective endothelin receptor antagonists. 1. Discovery of A-127722. J Med Chem 1996, 39, 5, 1039. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (I) | 20675 | 5-[(E)-2-nitroethenyl]-1,3-benzodioxole | 1485-00-3 | C9H7NO4 | 详情 | 详情 |
| (II) | 20676 | ethyl 3-(4-methoxyphenyl)-3-oxopropanoate | C12H14O4 | 详情 | 详情 | |
| (III) | 20677 | ethyl 3-(1,3-benzodioxol-5-yl)-2-(4-methoxybenzoyl)-4-nitrobutanoate | C21H21NO8 | 详情 | 详情 | |
| (IV) | 20678 | ethyl 3-(1,3-benzodioxol-5-yl)-5-(4-methoxyphenyl)-3,4-dihydro-2H-pyrrole-4-carboxylate | C21H21NO5 | 详情 | 详情 | |
| (V) | 20679 | ethyl (2S,3R,4R)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate | C21H23NO5 | 详情 | 详情 | |
| (VI) | 20680 | ethyl (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate | C21H23NO5 | 详情 | 详情 | |
| (VII) | 20681 | (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-1-(tert-butoxycarbonyl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylic acid | C24H27NO7 | 详情 | 详情 | |
| (VIII) | 20682 | (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-1-(tert-butoxycarbonyl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylic 1,1-dimethylpropionic anhydride | C29H35NO8 | 详情 | 详情 | |
| (IX) | 14694 | (S)-4-Benzyl-2-oxazolidinone; (4S)-4-Benzyl-1,3-oxazolan-2-one; (S)-(-)-4-Benzyl-2-oxazolidinone | 90719-32-7 | C10H11NO2 | 详情 | 详情 |
| (X) | 20684 | tert-butyl (2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-3-[[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl]-2-(4-methoxyphenyl)-1-pyrrolidinecarboxylate | C34H36N2O8 | 详情 | 详情 | |
| (XI) | 20685 | 2-Bromo-N,N-dibutylacetamide; N,N-Dibutylbromoacetamide | C10H20BrNO | 详情 | 详情 | |
| (XII) | 20686 | 2-[(2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-3-[[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl]-2-(4-methoxyphenyl)pyrrolidinyl]-N,N-dibutylacetamide | C39H47N3O7 | 详情 | 详情 |
合成路线2
该中间体在本合成路线中的序号：(IV)Cyclization of 5-(2-nitrovinyl)-1,3-benzodioxole (I) with ethyl 2-(4-methoxybenzoyl)acetate (II) by means of DBU in THF gives the 4-nitrobutyrate (III), which is reduced with H2 over Ni in ethanol to the corresponding amine, which undergoes immediate cyclization to give the pyrroline carboxylate (IV). Reduction of pyrroline (IV) with NaCNBH3 in THF affords the expected pyrrolidine as a mixture of the (trans,trans)-(V), (cis,cis)-(VI) and (cis,trans)-(VII) isomers. Using chromatography on silica gel, only the (cis,cis)-isomer (VI) is separated and completely isomerized to the (trans,trans)-isomer (V) by treatment with NaOEt in refluxing ethanol. Pure (trans,trans)-isomer (V) or the remaining mixture of (trans,trans)-(V) and (cis,trans)-(VII) is N-protected with Boc2O in dichloromethane to provide a mixture of carbamates. Then hydrolysis of the esters is performed with NaOH in ethanol/water at room temperature, and under these conditions only the (trans,trans)-isomer hydrolyzes, giving the racemic (trans,trans)-acid (VIII). Unreacted (cis,trans)-ester (VII) is easily removed by conventional methods. Condensation of the racemic acid (VIII) with the lithium salt of the chiral oxazolidinone (IX) by means of pivaloyl chloride yields the corresponding amide as a diastereomeric mixture of (X) and (XI) that are separated by chromatography. The desired isomer (XI) is deprotected with HCl in dioxane to afford the chiral pyrrolidine (XII), which is condensed with 2-bromo-N,N-dibutylacetamide (XIII) by means of diisopropylamine in acetonitrile to give the adduct (XIV). Finally, the chiral auxiliary of (XIV) is eliminated by means of LiOOH (LiOH + H2O2) in water.
| 【1】 Leeson, P.; Castañer, R.M.; Sorbera, L.A.; Castañer, J.; Atrasentan. Drugs Fut 2001, 26, 10, 939. |
| 【2】 Winn, M.; et al.; 2,4-Diarylpyrrolidine-3-carboxylic acids-potent ETA selective endothelin receptor antagonists. 1. Discovery of A-127722. J Med Chem 1996, 39, 5, 1039. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (I) | 20675 | 5-[(E)-2-nitroethenyl]-1,3-benzodioxole | 1485-00-3 | C9H7NO4 | 详情 | 详情 |
| (II) | 20676 | ethyl 3-(4-methoxyphenyl)-3-oxopropanoate | C12H14O4 | 详情 | 详情 | |
| (III) | 20677 | ethyl 3-(1,3-benzodioxol-5-yl)-2-(4-methoxybenzoyl)-4-nitrobutanoate | C21H21NO8 | 详情 | 详情 | |
| (IV) | 20678 | ethyl 3-(1,3-benzodioxol-5-yl)-5-(4-methoxyphenyl)-3,4-dihydro-2H-pyrrole-4-carboxylate | C21H21NO5 | 详情 | 详情 | |
| (V) | 20680 | ethyl (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate | C21H23NO5 | 详情 | 详情 | |
| (VI) | 20679 | ethyl (2S,3R,4R)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate | C21H23NO5 | 详情 | 详情 | |
| (VII) | 48684 | ethyl (2S,4S)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate | C21H23NO5 | 详情 | 详情 | |
| (VIII) | 20681 | (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-1-(tert-butoxycarbonyl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylic acid | C24H27NO7 | 详情 | 详情 | |
| (IX) | 10793 | [(4S)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]lithium | C10H10LiNO2 | 详情 | 详情 | |
| (X) | 48685 | tert-butyl (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-3-[[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl]-2-(4-methoxyphenyl)-1-pyrrolidinecarboxylate | C34H36N2O8 | 详情 | 详情 | |
| (XI) | 20684 | tert-butyl (2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-3-[[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl]-2-(4-methoxyphenyl)-1-pyrrolidinecarboxylate | C34H36N2O8 | 详情 | 详情 | |
| (XII) | 48686 | (4S)-3-[[(2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)pyrrolidinyl]carbonyl]-4-benzyl-1,3-oxazolidin-2-one | C29H28N2O6 | 详情 | 详情 | |
| (XIII) | 20685 | 2-Bromo-N,N-dibutylacetamide; N,N-Dibutylbromoacetamide | C10H20BrNO | 详情 | 详情 | |
| (XIV) | 20686 | 2-[(2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-3-[[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl]-2-(4-methoxyphenyl)pyrrolidinyl]-N,N-dibutylacetamide | C39H47N3O7 | 详情 | 详情 |