82586-54-7Relevant academic research and scientific papers
Continuous Flow Synthesis of ACE Inhibitors From N-Substituted l-Alanine Derivatives
Breen, Christopher P.,Jamison, Timothy F.
supporting information, p. 14527 - 14531 (2019/11/03)
A strategy for the continuous flow synthesis of angiotensin converting enzyme (ACE) inhibitors is described. An optimization effort guided by in situ IR analysis resulted in a general amide coupling approach facilitated by N-carboxyanhydride (NCA) activation that was further characterized by reaction kinetics analysis in batch. The three-step continuous process was demonstrated by synthesizing 8 different ACE inhibitors in up to 88 % yield with throughputs in the range of ≈0.5 g h?1, all while avoiding both isolation of reactive intermediates and process intensive reaction conditions. The process was further developed by preparing enalapril, a World Health Organization (WHO) essential medicine, in an industrially relevant flow platform that scaled throughput to ≈1 g h?1.
PROCESS FOR THE PREPARATION OF AMIDES OF N-[1-(S)-(ETHOXYCARBONYL)-3-PHENYLPROPYL]-L-ALANINE
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Page/Page column 21; 22, (2015/01/07)
A process for the production of amides of N-[1-(S)-(ethoxycarbonyl)-3-phenylpropyl]-L-alanine is described. The process can be used for the production of key intermediates and finally the ACE inhibitors such as Ramipril, Enalapril, Quinapril, Trandolapril, Delapril and Moexipril starting from N-[1-(S)-(ethoxycarbonyl)-3-phenylpropyl]-L-alanine by the reaction with the appropriate amines.
2′-Benzothiazolylthioesters of N-substituted alpha amino acids: Versatile intermediates for synthesis of ACE inhibitors
Singh, Girij Pal,Godbole, Himanshu M.,Nehate, Sagar P.,Mahajan, Pravin R.
, p. 243 - 248 (2007/10/03)
ACE inhibitors have been synthesized from novel active esters using simple reaction conditions in high diastereomeric selectivity. The active esters may be obtained from the corresponding carboxylic acids or their acid chlorides.
CRYSTALLINE FORM OF QUINAPRIL HYDROCHLORIDE AND PROCESS FOR PREPARING THE SAME
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Page 25;13;16, (2008/06/13)
A novel crystalline form of quinapril hydrochloride of formula (I). An amorphous form of quinapril hydrochloride substantially free of impurities, specially diketopiperazine compound, and conforming to pharmacopoeial specifications formed from the said novel crystalline form of quinapril hydrochloride of formula (I). The crystalline quinapril hydrochloride is in the form nitroalkane solvate in which the nitroalkane is nitromethane, nitroethane and nitropropane. Each such nitroalkane solvate having particular characteristic X- ray diffraction patterns. A process for preparation of amorphous from of quinapril hydrochloride, substantially free of impurities, specially diketopiperazine compound, and conforming to pharmacopoeial specifications, using the novel crystalline quinapril hydrochloride as an intermediate. The process involves obtaining free base compound of formula (V) by adjusting the pH of a solution of the benzyl ester maleate salt of quinapril of formula (V) between 7.5-8.5 in a mixture of water and an organic solvent; catalytic hydrogenation of this compound (V) in an alcoholic solvent in the presence of concentrated hydrochloric acid or hydrogen chloride dissolved in an alcoholic solvent and in the presence of catalytic amounts of Pd/C to obtain a residue containing formula (I); crystallization of the said residue by evaporating the alcoholic solvent from a nitroalkane solvent to give crystalline quinapril hydrochloride, associated with a solvate of the nitroalkane solvent, and drying the crystalline quinapril hydrochloride nitroalkane solvate at a temperature between 40°C and 45°C under vacuum to give amorphous quinapril hydrochloride of formula (I).
