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Study of the bromination of 1,5-dinitro-3-azabicyclo-[3.3.1]non-6-enes

“…The signal of the H-7 proton is observed in the 1 H NMR spectrum as a triplet (5.18 ppm, 3 J = 6.62 Hz) as a result of the concurrence of the vicinal constants from the interaction with the neighboring H-6 and H-8 atoms. Assignment of the signal of the H-7 proton was confirmed by the presence of the corresponding correlation peaks in the heteronuclear correlation HSQC (H-7/C (7) , 81.45 ppm) and HMBC (H-7/C (1) , H 7/C (5) , and H-7/NMe) spectra.…”

“…One of the methods of functionalizing the derivatives of 1,5-dinitro-3-azabicyclo[3.3.1]non-6-enes previously synthesized by us [4][5][6][7][8] may be the addition of electrophilic reagents at the double bond. It was shown previously that electrophilic addition of halogenating agents to 2-azanorborn-5-ene leads to the formation of rearranged products [9, 10], and addition of bromine and dihalogen iodates to 2-alkyl-2-azabicyclo[2.2.1]hept-5-ene and 2-alkyl-2-azabicyclo-[2.2.2]oct-5-ene leads to a quaternary ammonium salt containing an aziridinium ring [11,12].…”

“…Intense bands for the stretching vibrations of nitro groups were detected in the IR spectra of the compounds at 1550-1600 and 1350-1370, and bands of medium strength at 760-680 cm -1 corresponding to the vibrations of a C-Br bond [13]. The absence from the spectra of bands for the stretching vibrations of the C=C bond indicates the saturated character of compounds 2a-l. N For a more precise assignment of signals in the NMR spectra of the synthesized compounds the twodimensional correlation NMR spectra (HSQC, HMBC, COSY, NOESY) of 6-bromo-3-methyl-1,5-dinitro-3-azoniatricyclo[3.3.1.0 3,7 ]nonane tribromide (2a) and of the initial compound 1a were recorded. The 1 H NMR spectrum of compound 2a is a complex ten-spin system, however analysis of it is simplified by the presence in the molecule of the C (7) -N (3) bond, thanks to which the piperidine and cyclohexane rings are clearly fixed in a chair-chair conformation (Table 1).…”

“…A starting point for interpreting the NMR spectra may be served by the low field broadened doublet (5.73 ppm, 3 J = 6.62 Hz) of the H-6 proton at the carbon atom directly linked with halogen, and the singlet of the N-methyl group protons at 3.59 ppm, which have correlation peaks 1 J CH in the 2D HSQC spectrum with the signals of the carbon atoms at 53.06 and 55.01 respectively, and also cross peaks 2 J CH in the HMBC spectrum H-6/C (7) , H-6/C (5) and 3 J CH H-6/C (9) , H-6/C (8) , Me/C (4) , Me/C (2) , and Me/C (7) ( Table 2). The presence of a vicinal coupling constant between the protons of the methyl group and the C (7) atom indicates the formation in the molecule of a covalent bond between the C (7) -N (3) atoms.…”

“…The presence of a vicinal coupling constant between the protons of the methyl group and the C (7) atom indicates the formation in the molecule of a covalent bond between the C (7) -N (3) atoms. The signal of the H-7 proton is observed in the 1 H NMR spectrum as a triplet (5.18 ppm, 3 J = 6.62 Hz) as a result of the concurrence of the vicinal constants from the interaction with the neighboring H-6 and H-8 atoms.…”