Profil nečistot ključnega prekurzorja za sintezo zaviralca angiotenzinskih konvertaz

Testen, Ana (author), Kralj Cigić, Irena (mentor), Štefane, Bogdan (comentor)

Sinteze zaviralca angiotenzinskih konvertaz TCV-116 se večinoma razlikujejo v različnem reakcijskem zaporedju priprave posameznih segmentov molekule, tj. priprave bifeniltetrazolnega dela, benzimidazolskega obroča ter stranske estrske skupine. V doktorski disertaciji sem obravnavala dve različni sintezni poti za pripravo ključnega prekurzorja za sintezo aktivne učinkovine TCV-116. Z visokoločljivostno masno spektrometrijo, sklopljeno s tekočinsko kromatografijo visoke ločljivosti sem analizirala vzorce prekurzorja, pripravljene po dveh različnih sintezah in identificirala vse sorodne organske nečistote. Na osnovi predlaganih struktur spojin iz masnih spektrov in spektrov po tandemski masni spektrometriji sem določila vire oziroma vzroke za nastanek nečistot. V raziskavah sem večjo pozornost namenila sinteznim nečistotam, ki so v primerjavi z razgradnimi precej neraziskane. Nekatere strukture nečistot in mehanizem nastanka sem potrdila s ciljno sintezo in izolacijo, druge s stresnimi testi. Izkazalo se je, da največ sinteznih nečistot izhaja iz zadnje in predzadnje stopnje pri obeh sinteznih poteh. Pri prvi sintezi je odločilna stopnja reakcije esterifikacija, kjer se z uporabo 1-kloroetil cikloheksil karbonata tvori ester. Ugotovila sem, da ob tem poteka množica vzporednih reakcij z nečistotami, ki so prisotne v reagentu. Nečistote v reagentu sem zaznala z GC-MS analizo in jih je zaradi strukturne analogije težko odstraniti. Pri drugem postopku je največ nečistot povezanih s Suzuki reakcijo v predzadnji stopnji celotne sintezne poti. Sinteza tetrazolnega obroča in tritiliranje, ki sledita, ne odpravita sledov nastalih sorodnih snovi, postopki čiščenja pa so neuspešni za tovrstne spojine. Pokazala sem, da lahko z visokoločljivostnim masnim spektrometrom določim strukture nečistotam, ki so prisotne v sledovih in hkrati na osnovi strukture in ciljnega iskanja mas raziščem njihovo pojavnost v predhodnih stopnjah ter sklepam na njihov nastanek. Pokazala sem tudi, da lahko nastanek nečistot potrdim z enostavnimi stresnimi testi. Rezultati raziskav so pomembni za praktično izvedbo sinteze ključnega prekurzorja, hkrati pa širijo znanje o novih strukturah, predvsem na področju strukturne analize podobnih spojin z MS. Prisotnost nekaterih identificiranih sorodnih snovi v ključnem intermediatu lahko predstavlja potencialno tveganje za uporabnike, ter so lahko zdravju škodljive, ker zaradi svoje reaktivnosti povzročajo poškodbe DNK in so zato lahko potencialno mutagene.

• Language: Slovenian
• Keywords: visokoločljivostna masna spektrometrija, ključni prekurzor, zaviralec angiotenzinskih konvertaz, organske nečistote
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-122209
• COBISS.SI-ID: 39951875
• Publication date in RUL: 27.11.2020

Secondary language

• Language: English
• Title: Impurity profile of a key precursor for synthesis of angiotensin convertases inhibitor

Abstract

Syntheses of angiotensin convertases TCV-116, which are used for treatment of hypertension and other related cardiovascular diseases, mostly differ in reaction sequence. In general, there is benzimidazole part, biphenyltetrazole ring, and ester side chain. This research includes two different ways to prepare one of the main precursors for the synthesis of TCV-116. High resolution mass spectrometry hyphenated to high performance liquid chromatography was used to detect all present organic impurities in samples, prepared via two different synthetic strategies. Based on mass spectra and fragmentation patterns I have proposed chemical structures (structure) to each impurity detected and regarding target mass search in previous steps of synthesis I have determined its origin. Special attention to process-related organic impurities was given since degradation impurities are more or less known. Based on Further, I have proposed mechanism of occurrence for each impurity and confirmed its structure via target synthesis and isolation or by simple stress tests. I have found that majority of impurities develop during last or penultimate step of process in both cases. In first scenario, the last synthetic step is esterification, where 1-chloroethylcyclohexyl carbonate is added to generate key precursor. I have determined most impurities form out of impurities, present in reagent 1-chloroethyl cyclohexyl carbonate. By GC-MS screening, related substances were identified in this reagent. Because of structure analogy to key intermediate, impurities are difficult to remove. In the second synthesis, the largest number of impurities generates during Suzuki coupling reaction. Apparently, tetrazole synthesis and trityl protection formation do not remove the rest of impurities. I have shown that with high resolution mass spectrometer impurity traces can be identified and that target mass search can help discover cause or source for its creation. I have also shown structure confirmation can be done by simple stress tests. These results may have some potential applications in structural analysis of common compounds by mass spectrometry and could introduce some tips for synthesis of key precursor for angiotensin convertases inhibitor. Some identified impurities presence in key precursor can represent potential risk for users health, because are hazardous and can cause DNA damage due its reactivity.

• Keywords: high resolution mass spectrometry, angiotensin convertases inhibitor, key precursor, organic impurities