Sinteza in pretvorbe 3-amino-4-okso-4H-kinolizin-1-karbonitrila

Šuman, Timotej (author), Svete, Jurij (mentor)

V svojem diplomskem delu sem sintetiziral 1-ciano-4-okso-4H-kinolizin-3-diazonijev tetrafluoroborat iz metil (2Z)-2-benzamido-3-(dimetilamino)prop-2-enoata in 2-(piridin-2-il)acetonitrila. Sintezo sem izvedel enkrat na manjši 10 mmol skali in enkrat na večji 30 mmol skali. V prvi stopnji sinteze je potekla reakcija ciklokondenzacije med 2-(piridin-2-il)acetonitrilom kot dinukleofilom in metil (2Z)-2-benzamido-3-(dimetilamino)prop-2-enoatom kot dielektrofilom. Pri reakciji sta izstopila metanol in dimetilamin kot stranska produkta ciklokondenzacije, nastal pa je N-(1-ciano-4-okso-4H-kinolizin-3-il)benzamid. Enaminon, s katerim sem tvoril derivat 4H-kinolizin-4-ona, je vseboval zaščiteno aminsko skupino v obliki benzamida, ki je ostal vezan v biciklični strukturi na poziciji 3. Zaščiteno aminsko skupino sem nato v drugi stopnji sinteze s hidrolizo v kislem pretvoril v prost amin, pri čemer je izstopila zaščitna skupina v obliki benzojske kisline. V zadnji stopnji sinteze sem prost amin, ki je nastal v prejšnji stopnji, pretvoril v diazonijevo sol z uporabo NaNO2 in HBF4. Kot anion za stabilizacijo diazonijevega kationa sem uporabil tetrafluoroborat, ki z 1-ciano-4-okso-4H-kinolizin-3-diazonijevim kationom tvori stabilno diazonijevo sol. Te diazonijeve soli so uporabne za nadaljnje reakcije azo spajanja in uvajanja raznih nukleofilov na 4H-kinolizin-4-onski obroč.

• Language: Slovenian
• Keywords: Enaminoni, 4H-kinolizin-4-on, ciklokondenzacija, diazotiranje
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-148399
• COBISS.SI-ID: 162866435
• Publication date in RUL: 22.08.2023

Secondary language

• Language: English
• Title: Synthesis and conversions of 3-amino-4-oxo-4H-quinolizine-1-carbonitrile

Abstract

In my work for bachelor’s degree, 1-cyano-4-oxo-4H-quinolizine-3-diazonium tetrafluoroborate was synthesized from 2-(pyridin-2-yl)carbonitrile and methyl (2Z)-2-benzamido-3-(dimethylamino)prop-2-enoate as starting compounds. The synthesis was carried out first on a smaller 10 mmol scale and then on a bigger 30 mmol scale. The reaction between enaminone and the derivative of pyridine was a cyclocondensation reaction between 2-(pyridin-2-yl)carbonitrile, which acted as a dinucleophile, and methyl (2Z)-2-benzamido-3-(dimethylamino)prop-2-enoate, which acted as a dielectrophile. In this reaction, methanol and dimethylamine were the by-products of the cyclocondensation and N-(1-cyano-4-oxo-4H-quinolizin-3-yl)benzamide was formed as the main product. Enaminone, with which the derivative of 4H-quinolizin-4-one was formed, also contained the protected amine group in a form of a benzamide, which stayed bound in the bicyclic product at the position 3. The protected amino group was transformed with hydrochloric acid into the free amine and the protecting group was removed in a form of benzoic acid. In the last step of synthesis, the free amine, that was formed in the previous step, was converted into a diazonium salt using NaNO2 and HBF4. Tetrafluoroborate was used as an anion to stabilize the diazonium cation and a stable diazonium salt was obtained. This diazonium salt can be further used for the reactions of azo coupling or for introducing different functionalities to the 4H-quinolizin-4-one ring.

• Keywords: Enaminones, 4H-quinolizin-4-one, cyclocondensation, diazotation