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【结 构 式】

【分子编号】20677

【品名】ethyl 3-(1,3-benzodioxol-5-yl)-2-(4-methoxybenzoyl)-4-nitrobutanoate

【CA登记号】

【 分 子 式 】C21H21NO8

【 分 子 量 】415.39968

【元素组成】C 60.72% H 5.1% N 3.37% O 30.81%

与该中间体有关的原料药合成路线共 3 条

合成路线1

该中间体在本合成路线中的序号:(III)

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:(III)

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

合成路线3

该中间体在本合成路线中的序号:(III)

Condensation of 1,3-benzodioxole-5-carbaldehyde (XV) with nitromethane by means of ammonium acetate in HOAc gives the nitrostyrene (I), which is condensed with ethyl 2-(4-methoxybenzoyl)acetate (II) [obtained by reaction of acetophenone (XVI), diethyl carbonate and potassium tert-amyloxide] by means of NaOEt in THF to yield the 4-nitrobutyrate (III). Reductive cyclization of (III) with H2 over Raney-Ni in THF affords the (cis, cis)-pyrrolidine (VI), which is isomerized to the (trans,trans)-isomer (V) by means of NaOEt in refluxing ethanol. This racemic ester (V) is submitted to optical resolution with (S)-(+)-mandelic acid to provide the pure chiral ester (XVII). This compound is condensed with 2-bromo-N,N-dibutylacetamide (XIII) [obtained by reaction of 2-bromoacetyl bromide (XVIII) with dibutylamine (XIX) in toluene] by means of DIEA in acetonitrile to give the ethyl ester (XX), which is finally hydrolyzed with NaOH in hot ethanol.

1 Leeson, P.; Castañer, R.M.; Sorbera, L.A.; Castañer, J.; Atrasentan. Drugs Fut 2001, 26, 10, 939.
2 Winn, M.; Boyd, S.A.; Hutchins, C.W.; Tasker, A.S.; Von Geldern, T.W.; Kester, J.A.; Sorensen, B.K.; Szczepankiewicz, B.G.; Henry, K.J. Jr.; Liu, G.; Wittenberger, S.J.; King, S.A. (Abbott Laboratories Inc.); Novel benzo-1,3-dioxolyl- and benzofuranyl substd. pyrrolidine derivs. as endothelin antagonists. EP 0885215; WO 9730045 .
3 Jae, H.-S.; Hutchins, C.W.; Szczepankiewicz, B.G.; King, S.A.; Winn, M.; Boyd, S.A.; Henry, K.J.; Geldern, T.W.; Wittenberger, S.J.; Tasker, A.S.; Sorensen, B.K.; Kester, J.A. (Abbott Laboratories Inc.); Endothelin antagonists. WO 9906397 .
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
(VI) 20679 ethyl (2S,3R,4R)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate C21H23NO5 详情 详情
(XIII) 20685 2-Bromo-N,N-dibutylacetamide; N,N-Dibutylbromoacetamide C10H20BrNO 详情 详情
(XV) 10127 1,3-Benzodioxole-5-carbaldehyde; Heliotropine 120-57-0 C8H6O3 详情 详情
(XVI) 11041 4-Methoxyacetophenone; 1-(4-Methoxyphenyl)-1-ethanone 100-06-1 C9H10O2 详情 详情
(XVII) 20680 ethyl (2S,3S,4R)-4-(1,3-benzodioxol-5-yl)-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate C21H23NO5 详情 详情
(XVIII) 14005 2-Bromoacetyl bromide; Bromoacetyl bromide 598-21-0 C2H2Br2O 详情 详情
(XIX) 33492 N,N-dibutylamine; N-butyl-1-butanamine 111-92-2 C8H19N 详情 详情
(XX) 48687 ethyl (2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylate C31H42N2O6 详情 详情
Extended Information