KBS9: Bis propargylation of bridged cyclam
Prepared according to a previously described method. KBS1 (1.00 g, 4.46 mmol) was dissolved in acetonitrile (64 mL) and propargyl bromide (3.4 mL, 22.9 mmol) was added. The mixture was left to stir for 17 hours at room temperature. The white precipitate formed was collected by filtration in vacuo and washed with ice-cold acetonitrile (2 x 50 mL) to yield an off-white powder (1.89 g, 98%).
LRMS [ESI+] m/z 301.2 [M – H]+.
1H NMR (300 MHz, D2O) δ 3.50 (s, 4H), 3.40 – 3.27 (m, 7H), 2.88 (dq, J = 18.3, 7.2, 6.3 Hz, 9H), 2.03 – 1.89 (m, 4H).
Spectroscopic values were in agreement with those reported in the literature.
Earlier attempts not on GitHub.
KBS9-3 - 72%