(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylic acid -Drug Synthesis Database

【结构式】

【分子编号】50720

【品名】(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylic acid

【CA登记号】

【分子式】C₁₁H₁₂O₃

【分子量】192.21448

【元素组成】C 68.74% H 6.29% O 24.97%

与该中间体有关的原料药合成路线共 2 条

合成路线1 合成路线2

合成路线1

该中间体在本合成路线中的序号：(III)

Alternatively, the title compound was prepared by an asymmetric synthesis: The known racemic 2-ethyl-2,3-dihydro-2-benzofurancarboxylic acid (II) was resolved by means of (S)-(+)-2-phenylglycinol to furnish the desired (+)-enantiomer (III). After esterification of (III) using MeOH in the presence of SOCl2, the resultant methyl ester (IV) was treated with ammonium hydroxide, yielding amide (V). Subsequent dehydration of amide (V) with P2O5 in refluxing toluene gave nitrile (VI). Treatment of (VI) with EtOH in the presence of a catalytic amount of NaOMe produced an intermediate imidate, which was subsequently treated with ethylenediamine and HCl to generate the title imidazoline.

参考文献中间体

合成目标

【1】 Imbert, T.; Mayer, P. (Pierre Fabre Medicament); Method for preparing an optically pure benzofuran carboxylic acid and use thereof for preparing efaroxan. FR 2733983; US 5880296; WO 9635682 .

中间体序号	中间体编号	品名	分子式	供应商	用于合成
(II)	36673	2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylic acid	C₁₁H₁₂O₃	详情	详情
(III)	50720	(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylic acid	C₁₁H₁₂O₃	详情	详情
(IV)	50721	methyl (2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylate	C₁₂H₁₄O₃	详情	详情
(V)	50722	(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxamide	C₁₁H₁₃NO₂	详情	详情
(VI)	50723	(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carbonitrile	C₁₁H₁₁NO	详情	详情

合成路线2

该中间体在本合成路线中的序号：(III)

Addition of the in situ-generated Grignard reagent from 2-fluorobromobenzene (XV) to the chiral epoxide (XVI) furnished hydroxy ester (XVII). This was cyclized to the benzofuran derivative (XVIII) by using NaH in hot DMF. Hydrogenolysis of the benzyl ether (XVIII) provided the primary alcohol (XIX), which was then oxidized to the target carboxylic acid (III) employing the Jones reagent in acetone.

参考文献中间体

合成目标

【1】 Imbert, T.; Couture, K.; Mayer, P.; Mioskowski, C.; Gouverneur, V. (Pierre Fabre Medicament); Method for preparing 2-disubstd. 2,3-dihydrobenzofuran derivs.. FR 2780967; WO 0002836 .

中间体序号	中间体编号	品名	CAS号	分子式	供应商	用于合成
(III)	50720	(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylic acid		C₁₁H₁₂O₃	详情	详情
(XV)	50725	1-Bromo-2-fluorobenzene; o-Bromofluorobenzene; o-Fluorobromobenzene; 2-Fluorobromobenzene; 2-Bromofluorobenzene	1072-85-1	C₆H₄BrF	详情	详情
(XVI)	50726	(2R)-2-[(benzyloxy)methyl]-2-ethyloxirane; benzyl [(2R)-2-ethyloxiranyl]methyl ether		C₁₂H₁₆O₂	详情	详情
(XVII)	50727	(2R)-1-(benzyloxy)-2-(2-fluorobenzyl)-2-butanol		C₁₈H₂₁FO₂	详情	详情
(XVIII)	50728	(2R)-2-[(benzyloxy)methyl]-2-ethyl-2,3-dihydro-1-benzofuran; benzyl [(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-yl]methyl ether		C₁₈H₂₀O₂	详情	详情
(XIX)	50729	[(2R)-2-ethyl-2,3-dihydro-1-benzofuran-2-yl]methanol		C₁₁H₁₄O₂	详情	详情

Extended Information