3.1.3. General Procedure for the Synthesis of Amides 6–7

Dehydroabietylamine hydrochloride (1.0 g, 3.1 mmol) was mixed with an equimolar amount of 1- or 2-adamantanecarbonyl chloride (0.62 g, 3.1 mmol) in 30 mL of CH₃CN with the addition of Et₃N (0.56 mL, 4.0 mmol). The reaction mixture was stirred on a magnetic stirrer for 24 h at room temperature. Upon completion, the solvent was evaporated under vacuum. The solid residue was dissolved in CHCl₃ (20 mL) and washed with water (15 mL). The organic layer was dried over anhydrous Na₂SO₄ and filtered. The resultant liquid was evaporated under vacuum. The residue was purified using column chromatography on silica gel with hexane/ethyl acetate system, with a concentration gradient (EtOAc 0–25%) as an eluent.

N-abieta-8,11,13-trien-18-yladamantan-1-carboxamide (6). Yield 50%, white powder. M.p. 90 ^oC. IR (KBr) νmax 3363, 2906, 1639, 1525 cm⁻¹. ¹H NMR (400MHz, CDCl₃, δ, ppm, J/Hz): 6.88 (1H, d, J_12,14=1.7, H-14), 6.98 (1H, dd, J_{11, 12}=8.2, J_12,14=1.7, H-12), 7.16 (1H, d, J_{11, 12}=8.2, H-11), 0.91 (3H, s, Me-19), 1.21 (6H, d, J_{16, 15}=6.9, Me-16 and Me-17), 1.20 (3H, s, Me-20), 2.81 (1H, sept, J_{15, 16}=6.9, H-15), 2.28 (1H, d, ²J=12.3, H-1e), 3.17-3.22 and 3.08-3.13 (1H both, m, H-18), 2.85-2.91 and 2.73-2.79 (1H both, m, H-7), 1.99-2.02 (3H, m, H-26, H-27, H-28), 1.80-1.83 (6H, m, H-23, H-24, H-25), 1.84-1.89 (1H, m, H-6e), 1.42 (1H, d, ²J=13.0, H-3e), 1.32-1.39 (2H, m, H-5a, H-1a), 1.62-1.75 (8H, m, H-29, H-30, H-31, H-3a, H-2e), 1.22-1.30 (2H, m, H-6e, H-2a). ¹³C NMR (100MHz, CDCl₃, δ, ppm): 177.7 (C-21), 146.9 (C-9), 145.4 (C-13), 134.6 (C-8), 126.8 (C-14), 124.1 (C-11), 123.7 (C-12), 18.4 (Me-19), 23.84 and 23.80 (Me-17 and Me-16), 25.4 (Me-20), 33.3 (C-15), 46.2 (C-5), 28.0 (C-26, C-27, C-28), 18.5 (C-2), 18.9 (C-6), 30.4 (C-7), 36.4 (C-29, C-30, C-31), 39.3 (C-23, C-24, C-25), 38.3 (C-4), 37.5 (C-1), 37.3 (C-10), 36.2 (C-3), 49.5 (C-18), 40.8 (C-22). Found, m/z: 447.3490 [M]⁺. C₃₁H₄₅ON. Calculated, m/z: 447.3496.

N-abieta-8,11,13-trien-18-yladamantan-2-carboxamide (7). Yield 46%, white powder. M.p. 94 ^oC. IR (KBr) νmax 3311, 2904, 1642, 1542 cm⁻¹. ¹H NMR (400MHz, CDCl₃, δ, ppm, J/Hz):6.87 (1H, s, H-14), 6.97 (1H, d, J_{11, 12}=8.1, H-12), 7.15 (1H, d, J_{11, 12}=8.1, H-11), 0.92 (3H, s, Me-19), 1.20 (6H, d, J_{16, 15}=6.9, Me-16 and Me-17), 1.19 (3H, s, Me-20), 2.80 (1H, sept, J_{15, 16}=6.9, H-15), 2.27 (1H, d, ²J=12.7, H-1e), 2.73-2.94 (2H, m, H-7), 5.59 (1H, s, NH), 3.13-3.26 (2H, m, H-18), 2.39-2.47 (1H, m, H-23), 2.16-2.23 (2H, m, H-22, H-26), 1.63-1.80 (7H, m, H-24, H-29, H-25, H-31, H-30, H-3, H-6), 1.52-1.63 (3H, m, H-5a, H-1e, H-3), 1.80-2.00 (6H, m, H-24, H-29, H-25, H-31, H-28, H-27), 1.29-1.46 (4H, m, H-6, 2H-2, H-1a). ¹³C NMR (100MHz, CDCl₃, δ, ppm): 173.9 (C-21), 147.0 (C-9), 145.5 (C-13), 134.7 (C-8), 126.8 (C-14), 124.0 (C-11), 123.7 (C-12), 18.5 (Me-19), 23.8 and 23.9 (Me-17 and Me-16), 25.2 (Me-20), 33.3 (C-15), 45.6 (C-5), 50.0 (C-23), 29.96 and 30.04 (C-22, C-26), 27.24 and 27.36 (C-27, C-28), 18.5 (C-2), 18.9 (C-6), 30.2 (C-7), 49.5 (C-18), 33.16 and 33.21 (C-25, C-31), 38.20 and 38.26 (C-25, C-31, C-4), 36.3 (C-3), 37.22, 37.31, 37.33 (C-10, C-1, C-30). Found, m/z: 447.3503 [M]⁺. C₃₁H₄₅ON. Calculated, m/z: 447.3500.