CONTRIBUTION TO CINCHONA ALKALOIDS CHEMISTRY

Ph.D. Thesis Abstract Contribution to cinchona alkaloids chemistry
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The reaction was conducted with an diluted solution of O-mesilcinchonine 9 (10%
concentration), at reflux, in a nitrogen atmosphere, using pure water. The end of the reaction was
verified by thin layer cromatography. The purification of 13 compund is done on a silica gel
colummn, using MTBE:MeOH=3:1 as a mobile phase. The obtaining of the product was
confirmed by H-RMN, IR spectrometry and elemental and mass analisys.
Beginning from the premise that the reaction is not favorized by the presence of the
protons in the reaction environment[147], we obtained methasulphonic acid as a secondary
product. We followed the infuence of the basic compound addition over the synthesis yield of
compound 13. For this study we added basic compounds, in order to neutralize the
methansulphonic acid that was formed in this reaction. We followed the influence of the
following compounds: NaHCO3, Na2CO3, NaOH, sodium benzoate. The carbonates generate
hidroxyl trough water hydrolysis, the same happens if we dissolve Na OH in water. The sodium
benzoate was introduced in the reaction mixture because the literature presents data on the
influence of these compounds in the transposition reaction of the cinchona alkaloids. [130]
Results are presented in Table 2.3, figure 2.3.
Table nr.2.3. The reaction conditions of compound 13
Proba Bază
Concentrație
(%)
9
Timp
(ore)
Randament
(%)
1 NaHCO3 8 16 23
2 Na2CO3 10 5 39
3 NaOH 5 3 52
4 BeNa 10 4 30
5 Apă - 4 51