# Novel Adamantane Derivatives: Synthesis, Cytotoxicity and Antimicrobial Properties
## 4 Discussion
### NMR Spectra Analysis  
The analysis of the \({}^{1}\)H NMR and \({}^{13}\)C NMR spectra made it possible to identify and confirm the chemical structure of the obtained substances and the correctness of their synthesis.  
The derivatives of 3-aminotricyclo[3.3.1.137]decan-1-ol (**2**,**3**) on the \({}^{1}\)H NMR spectra possessed a characteristic singlet signal for the proton of the =CH group at 8.51-8.54 ppm. On the \({}^{13}\)C NMR spectra, the signal for the carbon atom of the =CH group appeared at 8 149.26 ppm (**2**) and 149.53 ppm (**3**). The presence of this signal both on the \({}^{1}\)H NMR and \({}^{13}\)C NMR confirmed the correctness of the synthesis. For the derivatives (**2**,**3**), on the \({}^{1}\)H NMR spectra, a singlet signal for the proton of hydroxyl group was found at 8 4.53-4.56 ppm.  
In the case of the derivatives of tricylcol[3.3.1.137]decan-1-amine (**5**-**10**), on the \({}^{1}\)H NMR spectra, a singlet signal for the proton of the =CH group was present in the range of 8 8.16-8.62 ppm. The carbon atom of =CH on the \({}^{13}\)C NMR spectra for these substances (**5**-**10**) appeared in the range of 8 147.15-149.35 ppm.  
The correctness of the synthesis of the novel derivatives of 1-(tricylcol[3.3.1.137]decan-1-yl)methanamine (**13**-**15**) was confirmed with the \({}^{1}\)H NMR spectroscopy based on the presence of singlet signals for a proton of CH\({}_{2}\) and the =CH group, which appeared at 8 3.15-3.41 ppm and 8 8.43-10.14 ppm, respectively. The carbon atoms of CH\({}_{2}\) and the =CH group of compounds **13**-**15** gave signals on the \({}^{13}\)C NMR spectra in the range of 8 65.85-73.73 ppm (CH\({}_{2}\)) and 8 148.75-148.92 ppm (=CH). For compound **16**, we found a characteristic signal for =Cadamantane at 8 173.61 ppm because this condensation reaction was carried out with ketone.  
On the \({}^{1}\)H NMR spectra of the hydrazide of 1-adamantanecarboxylic acid (**19**), we found characteristic singlet signals for protons that corresponded to the NH (8 9.13 ppm) and NH\({}_{2}\) groups (8 4.04 ppm). On the \({}^{13}\)C NMR spectra for this compound, signals for carbon atoms were found in the expected range of chemical shift.  
The hydrazide-hydrazones of 1-adamantanecarboxylic acid (**20**-**21**) obtained in the reaction with aldehydes possessed two typical signals for this class of compounds on the \({}^{1}\)H NMR spectra. One singlet signal for the proton of the =CH group was found in the range of 8 7.94-9.13 ppm, and the other singlet signal for the proton of the NH group was found at 8 9.12-10.84 ppm. On the \({}^{13}\)C NMR spectra for compounds **20**-**21**, a signal for the carbon atom of the =CH group appeared around 8 147 ppm, whereas for derivatives **22**-**23**, signals for =Cadamantane were found at 8 168.24 ppm (compound **22**) and 8 167.86 ppm (compound **23**).  
Signals for other aliphatic and aromatic fragments of obtained substances on the \({}^{1}\)H NMR and \({}^{13}\)C NMR spectra were found at the expected values of chemical shift.  
The examples of the \({}^{1}\)H NMR spectra of the synthesized adamantane derivatives are presented in Supplementary Materials (Figures S25-S27).