SYNTHESIS OF SMALL MOLECULES NOP/MOP AGONISTS FOR TREATMENT OF PAIN AND RHODIUM CATALYSIS FOR NATURAL PRODUCTS SYNTHESIS The great interest in treatment of acute and chronic pain induced the study and the development of several potential drugs acting as agonists or antagonists of opioid receptor and that was also supported by the major-market sales of painkiller drugs steady 4.5% annual growth, expanding from $14 billion in 2005 to more than $22 billion in 20151. There is a growing interest of the pharmaceutical companies to develop new drugs more potent, selective to opioid receptors, and with less side effects as tolerance and dependence, last but not least, only one drug with one pharmacodinamic a pharmacokinetic. Significant efforts have been made in exploring a multi-target approach to reduce tolerance of MOP agonists even involving NOP-opioid system to modulate side-effects. This project has been developed following two different synthetic strategy:  the first one involved the synthesis of dual-targeted activity in a single chemical entity, in other words a single one agonist selective for NOP and MOP receptor, specifically Cebranopadol because it is the best ligand invented by Grunenthal company. It has been synthetized by using a retrosynthetic approach different from that one of Grunenthal reserchers with a good yield and a single diasteroisomer as the following synthetic scheme (scheme 1). The starting material was cyclohexanedione monoethylene acetal as first step to obtain the tertiary alcohol with 70 % of yield in THF, overnight. The following step was to obtain the azide through indium tribromide and trimethyl silyl azide at room temperature in 50% yield2. Once obtained the azide, this one was reduced by LiAlH4 in THF overnight in quantitative yield to have the primary amine (10) that underwent reductive amination. The intermediate obtained was a tertiary amine (11) in quantitative yield that was subjected to acetal hydrolysis moiety in acetone and HCl under reflux to obtain a ketone (12) with 81 % of yield ready to react with the indole through an Oxa-Pictet Spengler reaction with 50 % of yield. The reaction allowed us to have the final product A4 as single diastereoisomer (E) without any further purification step.  The second one involved the synthesis of a bivalent agonist made by two pharmacophoric entities, Ro 65-6570 as best NOP agonist and fentanyl derivatives made by Ruben Vardanian as best MOP agonists, linked by an appropriate spacer as the following example (figure 1)3. Ro 65-6570 was functionalyzed on the nitrogen amide by using bromo-propyl amine boc-protected (24) and then with the acid moiety of the maleimidic derivative (27) to obtain the final product (28): a NOP pharmacophore modified (figure 2). Fentanyls were thought to be functionalyzed to better react with the NOP ligand, so their best site susceptible to modifications was the alkene moiety on their final chain that could be involved in thiol-ene reaction4 (scheme 2). Once functionalized, Fentanyls reacted with their –SH moiety on the alkene of maleimid derivative (28) through a thio-Michael reaction base-catalysed to give the product in 15‘ and in quantitative yields (scheme 3). In conclusion, Cebranopadol was tested through a calcium mobilization assay with cells coexpressing NOP or classical receptors and chimeric G proteins and behaved as full agonist showing very similar potency at NOP and MOP receptors. The three chimeric compounds: Ro 65-6570/RR4, Ro 65-6570/RR6, Ro 65-6570/RR7 were tested by GTPγS functional assay and the potency of RR4-Ro and RR7-Ro was similar to that of fentanyl, while RR6-Ro was 5 fold less potent. The efficacy of all bivalent compounds was significantly lower than that of fentanyl. In other words all RR-Ro derivatives behaved as partial agonists at the MOP receptor. The potency of RR4-Ro and RR7-Ro was similar to that of the standard Ro 65-6570 while RR6-Ro was 3 fold less potent. All bivalent compounds elicited similar maximal effects as Ro 65-6570 behaving as NOP full agonists. In the second chapter of my thesis, I’ve synthetized tetrahydrothiophene by using some different starting materials and rhodium catalysts. The starting materials reacted with rhodium catalyst and aryl-iodonium salts as donor/acceptor carbenoids source, that generated carbynes with the metal. The aim of the project was to obtain tetrahydrothiophene rings and to improve the yield and the diastereoselectivity. The first starting materials was 2-(3-(methylthio)propyl)furan and 2-(3(methylthio)propyl)thiophene and I’ve obtained three final compounds in good yield and diastereomeric ratio as the following (scheme 4).Then I’ve been used (Z)-dec-4-en-1-yl(methyl)sulfane (3c) to obtain the following products (scheme 5).

SYNTHESIS OF SMALL MOLECULES NOP/MOP AGONISTS FOR TREATMENT OF PAIN AND RHODIUM CATALYSIS FOR NATURAL PRODUCTS SYNTHESIS Il grande interesse nel trattamento del dolore acuto e cronico ha portato allo studio e allo sviluppo di numerosi potenziali farmaci che agiscono come agonisti o antagonisti dei recettori oppioidi e questo processo è stato infatti supportato da un mercato farmaceutico in costante espansione del 4,5% anno, da 14 miliardi di dollari nel 2005 a più di 22 miliardi di dollari nel 20151. C’è un forte interesse da parte delle industrie farmaceutiche di sviluppare potenti farmaci, selettivi per i recettori del dolore e con meno effetti collaterali ma anche e soprattutto con un’unica farmacodinamica e farmacocinetica. Questo progetto è stato sviluppato seguendo due differenti strategie:  La prima coinvolge la sintesi di un composto con duplice attività in una singola entità chimica, in altre parole un singolo agonista per il recettore NOP e MOP, in modo specifico il Cebranopadol perché è il miglior ligando brevettato dalla ditta Grunenthal. Il composto è stato sintetizzato usando un approccio retrosintetico differente dai ricercatori dell’azienda tedesca con una buona resa e in unico diastereoisomero come descritto nello schema 1. Il composto di partenza usato è stato il 1,4-cicloesan-dione monoetilen acetale nel primo step sintetico per ottenere l’alcol terziario col 70% di resa in THF. 1 Anupara Koneru et al. Global Journal of Pharmacology 3 (3), 2009, 149-153. Lo step successivo era ottenere l’azide mediante l’uso di indio tribromuro e trimetil silil azide a temperatura ambiente col 50% di resa 2. Una volta ottenuta l’azide, questa viene ridotta con LiAlH4 in THF e tenuta in agitazione per tutta la notte per ottenere con resa quantitative l’ammina primaria (10) che subisce poi amminazione riduttiva per ottenere infine un’ammina terziaria (11) con resa quantitativa. L’ammina terziaria (11) subisce l’idrolisi della funzionalità acetalica in acetone e HCl a riflusso per ottenere il chetone con 80% di resa pronto a reagire con il nucleo indolico (12) mediante una reazione di Oxa-Pictet Spengler con 50% di resa. La reazione ci ha permesso di ottenere il composto finale A4 come singolo diastereoisomero senza successivi processi di purificazione. Schema 1 2 Walsh T. et al., tetrahedron, 57, 2001, 5233-5241. 3 Mei-Chuan Ko et al., The journal of pain, Vol.10, N°5, 2009, 509-516.  La seconda include la sintesi di un agonista bivalente costituito da due entità farmacoforiche, Ro 65-6570 come miglior agonista del recettore NOP e un analogo del Fentanile, sintetizzato da Ruben Vardanian, dall’Università dell’Arizona, come migliore ligando del recettore MOP legati da uno spacer come nell’esempio seguente (figura 1). Figura 1 Il Ro 65-6570 è stato funzionalizzato sull’azoto lattamico usando la bromo propil amina protetta come Boc (24) che a sua volta è stata condensate con la funzionalità acida di un derivato maleimidico (27) per ottenere il prodotto finale (28): un farmacoforo NOP modificato. (figura 2). Figura 2 I Fentanili invece sono stati funzionalizzati per reagire col ligando NOP, per cui il sito incline a subire maggiori modifiche è la funzionalità alchenica lungo la catena finale mediante una reazione di thiol-ene (schema 2).3 3 Dondoni et al., Chem. Soc. Rew. 2012, 41, 573-586. Schema 2 Una volta funzionalizzati con il gruppo tiolico, i fentanili effettuano una reazione di thiol-Michael sul doppio legame maleimmidico del derivato NOPper produrre i derivati desiderati in 15 minuti e con resa quantitativa. Schema 3 In conclusione, il Cebranopadol è stato testato attraverso un saggio di mobilitazione del calcio con cellule che co-esprimono il recettore NOP o i recettori classici e le proteine G chimeriche e agiscono come agonisti pieni mostrando una potenza molto simile per i recettori NOP e MOP. I tre composti chimerici: Ro 65-6570/RR4, Ro 65-6570/RR6, Ro 65-6570/RR7 sono stati testati mediante il saggio funzionale GTPγS e la potenza di RR4-Ro e RR7-Ro è simile a quella dei fentanili, mentre RR6-Ro è 5 volte meno potente. L’efficacia di tutti i composti bivalenti era significativamente più basso del fentanile. In alter parole, tutti i derivati RR-Ro si comportano come agonisti parziali per il recettore MOP. La potenza di RR4-Ro e RR7-Ro è simile a quella del Ro 656570 mentre RR6-Ro è 3 volte meno potente. Tutti i composti bivalenti esplicano un effetto simile al Ro 65-6570 agendo da NOP agonisti pieni. Nel secondo capitolo della mia tesi, sono stati sintetizzati dei tetraidrotiofeni pertendo da alcuni composti iniziali e da catalizzatori al rodio. I composti di partenza con sali di aril iodonio etil diazoacetato come fonte di carbenoidi donatori/accettori che generano carbini mediante catalizzatori al rodio. Lo scopo del progetto è di ottenere questi tetraidrotiofeni in modo diastereoselettivo e migliorare le rese. I composti di partenza sono il 2-(3-(metiltio)propil)furano e il 2-(3(metiltio)propil)tiophene come si può osservare dallo schema 4 che permettono di ottenere i composti finali con buona resa e diastereoselettività. È stato utilizzato infine il (Z)-dec-4-en-1-il(metil)sulfano (3c) per ottenere i seguenti prodotti (schema 5).

Synthesis of small Molecules Nop/Mop agonists for treatment of pain and rhodium catalysis for natural products synthesis.

BIANCO, Sara
2016

Abstract

SYNTHESIS OF SMALL MOLECULES NOP/MOP AGONISTS FOR TREATMENT OF PAIN AND RHODIUM CATALYSIS FOR NATURAL PRODUCTS SYNTHESIS The great interest in treatment of acute and chronic pain induced the study and the development of several potential drugs acting as agonists or antagonists of opioid receptor and that was also supported by the major-market sales of painkiller drugs steady 4.5% annual growth, expanding from $14 billion in 2005 to more than $22 billion in 20151. There is a growing interest of the pharmaceutical companies to develop new drugs more potent, selective to opioid receptors, and with less side effects as tolerance and dependence, last but not least, only one drug with one pharmacodinamic a pharmacokinetic. Significant efforts have been made in exploring a multi-target approach to reduce tolerance of MOP agonists even involving NOP-opioid system to modulate side-effects. This project has been developed following two different synthetic strategy:  the first one involved the synthesis of dual-targeted activity in a single chemical entity, in other words a single one agonist selective for NOP and MOP receptor, specifically Cebranopadol because it is the best ligand invented by Grunenthal company. It has been synthetized by using a retrosynthetic approach different from that one of Grunenthal reserchers with a good yield and a single diasteroisomer as the following synthetic scheme (scheme 1). The starting material was cyclohexanedione monoethylene acetal as first step to obtain the tertiary alcohol with 70 % of yield in THF, overnight. The following step was to obtain the azide through indium tribromide and trimethyl silyl azide at room temperature in 50% yield2. Once obtained the azide, this one was reduced by LiAlH4 in THF overnight in quantitative yield to have the primary amine (10) that underwent reductive amination. The intermediate obtained was a tertiary amine (11) in quantitative yield that was subjected to acetal hydrolysis moiety in acetone and HCl under reflux to obtain a ketone (12) with 81 % of yield ready to react with the indole through an Oxa-Pictet Spengler reaction with 50 % of yield. The reaction allowed us to have the final product A4 as single diastereoisomer (E) without any further purification step.  The second one involved the synthesis of a bivalent agonist made by two pharmacophoric entities, Ro 65-6570 as best NOP agonist and fentanyl derivatives made by Ruben Vardanian as best MOP agonists, linked by an appropriate spacer as the following example (figure 1)3. Ro 65-6570 was functionalyzed on the nitrogen amide by using bromo-propyl amine boc-protected (24) and then with the acid moiety of the maleimidic derivative (27) to obtain the final product (28): a NOP pharmacophore modified (figure 2). Fentanyls were thought to be functionalyzed to better react with the NOP ligand, so their best site susceptible to modifications was the alkene moiety on their final chain that could be involved in thiol-ene reaction4 (scheme 2). Once functionalized, Fentanyls reacted with their –SH moiety on the alkene of maleimid derivative (28) through a thio-Michael reaction base-catalysed to give the product in 15‘ and in quantitative yields (scheme 3). In conclusion, Cebranopadol was tested through a calcium mobilization assay with cells coexpressing NOP or classical receptors and chimeric G proteins and behaved as full agonist showing very similar potency at NOP and MOP receptors. The three chimeric compounds: Ro 65-6570/RR4, Ro 65-6570/RR6, Ro 65-6570/RR7 were tested by GTPγS functional assay and the potency of RR4-Ro and RR7-Ro was similar to that of fentanyl, while RR6-Ro was 5 fold less potent. The efficacy of all bivalent compounds was significantly lower than that of fentanyl. In other words all RR-Ro derivatives behaved as partial agonists at the MOP receptor. The potency of RR4-Ro and RR7-Ro was similar to that of the standard Ro 65-6570 while RR6-Ro was 3 fold less potent. All bivalent compounds elicited similar maximal effects as Ro 65-6570 behaving as NOP full agonists. In the second chapter of my thesis, I’ve synthetized tetrahydrothiophene by using some different starting materials and rhodium catalysts. The starting materials reacted with rhodium catalyst and aryl-iodonium salts as donor/acceptor carbenoids source, that generated carbynes with the metal. The aim of the project was to obtain tetrahydrothiophene rings and to improve the yield and the diastereoselectivity. The first starting materials was 2-(3-(methylthio)propyl)furan and 2-(3(methylthio)propyl)thiophene and I’ve obtained three final compounds in good yield and diastereomeric ratio as the following (scheme 4).Then I’ve been used (Z)-dec-4-en-1-yl(methyl)sulfane (3c) to obtain the following products (scheme 5).
TRAPELLA, Claudio
MANFREDINI, Stefano
File in questo prodotto:
File Dimensione Formato  
TESI DOTTORATO - SARA BIANCO.pdf

accesso aperto

Tipologia: Tesi di dottorato
Licenza: PUBBLICO - Pubblico senza Copyright
Dimensione 10.37 MB
Formato Adobe PDF
10.37 MB Adobe PDF Visualizza/Apri

I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/2403239
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact