【药物名称】Alvimopan hydrate, ADL-8-2698, LY-246736 dihydrate, Entereg
化学结构式(Chemical Structure):
参考文献No.42490
标题:Trisubstd.-piperidinyl-N-alkylcarboxylates as opioid antagonists
作者:Prather, D.E.; Werner, J.A.; Wad, J.A.; Frank, S.A. (Eli Lilly and Company)
来源:EP 0984004
合成路线图解说明:

LY246736 dihydrate is prepared in 12 steps from 1,3-dimethyl-4-piperidone (I) in 6.2% yield as depicted in Scheme 20754901a. Piperidinol (II) can be prepared from (I) using standard methodology. Selective elimination to tetrahydropyridine (IV) is accomplished by the cis-thermal elimination of an ethyl carbonate (III) at 190 C in refluxing Decalin(R). This maintains the stereochemistry at C-3, following resolution of carbonate (III) with di-p-toluoyl-D-tartaric acid ((+)-DDTA), and also enables the trans-stereochemistry of the methyl groups to be established in the next step. Alkylation of the metalloenamine with dimethyl sulfate at -50 C proceeds both regio- and stereospecifically, giving the trans-3,4-dimethyl-gamma-alkylation product (V). Reduction of the enamine with NaBH4 and N,O-didealkylation with phenyl chloroformate followed by HBr/AcOH gives the chiral 3,4-dimethyl-4-arylpiperidine (VII). The benzyl group of the N-substituent is introduced via a nonselective benzylation of the Michael adduct dianion at -20 C followed by a highly efficient crystallization of the (3R,4R,alphaS)-hydrochloride (VIII) from methanol. The undesired diastereomer can be epimerized (LDA, H2O) and recycled to afford additional (VIII). Hydrolysis of the ester with NaOH, DCC coupling of the glycine ester, and hydrolysis of the ester with NaOH in ethanol/water completes the synthesis. The crystalline dihydrate (X) is isolated directly from the saponification reaction mixture upon neutralization with hydrochloric acid (overall yield 6.2% with one recycle of (3R,4R,alphaR)-isomer of (VIII).

参考文献No.276933
标题:LY246736 Dihydrate
作者:Pohland, R.C.; Franklin, R.B.; Cantrell, B.E.; Means, J.R.; Leander, J.D.; Parli, C.J.; Francis, P.C.; Zimmerman, D.M.; Gidda, J.S.; Werner, J.A.
来源:Drugs Fut 1994,19(12),1078
合成路线图解说明:

LY246736 dihydrate is prepared in 12 steps from 1,3-dimethyl-4-piperidone (I) in 6.2% yield as depicted in Scheme 20754901a. Piperidinol (II) can be prepared from (I) using standard methodology. Selective elimination to tetrahydropyridine (IV) is accomplished by the cis-thermal elimination of an ethyl carbonate (III) at 190 C in refluxing Decalin(R). This maintains the stereochemistry at C-3, following resolution of carbonate (III) with di-p-toluoyl-D-tartaric acid ((+)-DDTA), and also enables the trans-stereochemistry of the methyl groups to be established in the next step. Alkylation of the metalloenamine with dimethyl sulfate at -50 C proceeds both regio- and stereospecifically, giving the trans-3,4-dimethyl-gamma-alkylation product (V). Reduction of the enamine with NaBH4 and N,O-didealkylation with phenyl chloroformate followed by HBr/AcOH gives the chiral 3,4-dimethyl-4-arylpiperidine (VII). The benzyl group of the N-substituent is introduced via a nonselective benzylation of the Michael adduct dianion at -20 C followed by a highly efficient crystallization of the (3R,4R,alphaS)-hydrochloride (VIII) from methanol. The undesired diastereomer can be epimerized (LDA, H2O) and recycled to afford additional (VIII). Hydrolysis of the ester with NaOH, DCC coupling of the glycine ester, and hydrolysis of the ester with NaOH in ethanol/water completes the synthesis. The crystalline dihydrate (X) is isolated directly from the saponification reaction mixture upon neutralization with hydrochloric acid (overall yield 6.2% with one recycle of (3R,4R,alphaR)-isomer of (VIII).

参考文献No.283412
标题:Selective "cis-dehydration" of 3-methyl-4-piperidinols via thermal elimination of carbonates and its application in synthesis
作者:Werner, J.A.; Cerbone, L.R.
来源:203rd ACS Natl Meet (April 5-10, San Francisco) 1992,Abst ORGN 409
合成路线图解说明:

LY246736 dihydrate is prepared in 12 steps from 1,3-dimethyl-4-piperidone (I) in 6.2% yield as depicted in Scheme 20754901a. Piperidinol (II) can be prepared from (I) using standard methodology. Selective elimination to tetrahydropyridine (IV) is accomplished by the cis-thermal elimination of an ethyl carbonate (III) at 190 C in refluxing Decalin(R). This maintains the stereochemistry at C-3, following resolution of carbonate (III) with di-p-toluoyl-D-tartaric acid ((+)-DDTA), and also enables the trans-stereochemistry of the methyl groups to be established in the next step. Alkylation of the metalloenamine with dimethyl sulfate at -50 C proceeds both regio- and stereospecifically, giving the trans-3,4-dimethyl-gamma-alkylation product (V). Reduction of the enamine with NaBH4 and N,O-didealkylation with phenyl chloroformate followed by HBr/AcOH gives the chiral 3,4-dimethyl-4-arylpiperidine (VII). The benzyl group of the N-substituent is introduced via a nonselective benzylation of the Michael adduct dianion at -20 C followed by a highly efficient crystallization of the (3R,4R,alphaS)-hydrochloride (VIII) from methanol. The undesired diastereomer can be epimerized (LDA, H2O) and recycled to afford additional (VIII). Hydrolysis of the ester with NaOH, DCC coupling of the glycine ester, and hydrolysis of the ester with NaOH in ethanol/water completes the synthesis. The crystalline dihydrate (X) is isolated directly from the saponification reaction mixture upon neutralization with hydrochloric acid (overall yield 6.2% with one recycle of (3R,4R,alphaR)-isomer of (VIII).

参考文献No.801687
标题:Synthesis of picenadol via metalloenamine alkylation methodology
作者:Copley-Merriman, C.R.; Maki, J.; Barnett, C.J.
来源:J Org Chem 1989,544795-800
合成路线图解说明:

LY246736 dihydrate is prepared in 12 steps from 1,3-dimethyl-4-piperidone (I) in 6.2% yield as depicted in Scheme 20754901a. Piperidinol (II) can be prepared from (I) using standard methodology. Selective elimination to tetrahydropyridine (IV) is accomplished by the cis-thermal elimination of an ethyl carbonate (III) at 190 C in refluxing Decalin(R). This maintains the stereochemistry at C-3, following resolution of carbonate (III) with di-p-toluoyl-D-tartaric acid ((+)-DDTA), and also enables the trans-stereochemistry of the methyl groups to be established in the next step. Alkylation of the metalloenamine with dimethyl sulfate at -50 C proceeds both regio- and stereospecifically, giving the trans-3,4-dimethyl-gamma-alkylation product (V). Reduction of the enamine with NaBH4 and N,O-didealkylation with phenyl chloroformate followed by HBr/AcOH gives the chiral 3,4-dimethyl-4-arylpiperidine (VII). The benzyl group of the N-substituent is introduced via a nonselective benzylation of the Michael adduct dianion at -20 C followed by a highly efficient crystallization of the (3R,4R,alphaS)-hydrochloride (VIII) from methanol. The undesired diastereomer can be epimerized (LDA, H2O) and recycled to afford additional (VIII). Hydrolysis of the ester with NaOH, DCC coupling of the glycine ester, and hydrolysis of the ester with NaOH in ethanol/water completes the synthesis. The crystalline dihydrate (X) is isolated directly from the saponification reaction mixture upon neutralization with hydrochloric acid (overall yield 6.2% with one recycle of (3R,4R,alphaR)-isomer of (VIII).

参考文献No.801688
标题:Application of metalated enamines to alkaloid synthesis. An expedient approach to the synthesis of morphine-based analgesics
作者:Robey, R.L.; Evans, D.A.; Zimmerman, D.M.; Mitch, C.H.; Thomas, R.C.
来源:J Am Chem Soc 1980,1025955-6
合成路线图解说明:

LY246736 dihydrate is prepared in 12 steps from 1,3-dimethyl-4-piperidone (I) in 6.2% yield as depicted in Scheme 20754901a. Piperidinol (II) can be prepared from (I) using standard methodology. Selective elimination to tetrahydropyridine (IV) is accomplished by the cis-thermal elimination of an ethyl carbonate (III) at 190 C in refluxing Decalin(R). This maintains the stereochemistry at C-3, following resolution of carbonate (III) with di-p-toluoyl-D-tartaric acid ((+)-DDTA), and also enables the trans-stereochemistry of the methyl groups to be established in the next step. Alkylation of the metalloenamine with dimethyl sulfate at -50 C proceeds both regio- and stereospecifically, giving the trans-3,4-dimethyl-gamma-alkylation product (V). Reduction of the enamine with NaBH4 and N,O-didealkylation with phenyl chloroformate followed by HBr/AcOH gives the chiral 3,4-dimethyl-4-arylpiperidine (VII). The benzyl group of the N-substituent is introduced via a nonselective benzylation of the Michael adduct dianion at -20 C followed by a highly efficient crystallization of the (3R,4R,alphaS)-hydrochloride (VIII) from methanol. The undesired diastereomer can be epimerized (LDA, H2O) and recycled to afford additional (VIII). Hydrolysis of the ester with NaOH, DCC coupling of the glycine ester, and hydrolysis of the ester with NaOH in ethanol/water completes the synthesis. The crystalline dihydrate (X) is isolated directly from the saponification reaction mixture upon neutralization with hydrochloric acid (overall yield 6.2% with one recycle of (3R,4R,alphaR)-isomer of (VIII).

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