1,2,3,4-TETRAHYDROISOQUINOLINE-1-CARBOXYLIC ACID DERIVATIVES
2495
Selected Data
N-Cyclohexyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxa-
mide (3a). Yield: 0.46 g (89%), a white crystalline solid, mp 138–140 ꢀC; 1H
(CDCl3): d 7.11 (1H, s, C6H2), 7.07 (1H, d, J ¼ 7.0 Hz, NH), 6.55 (1H, s, C6H2),
4.43 (1H, s, CHN), 3.86 (3H, s, OCH3), 3.84 (3H, s, OCH3), 3.77–3.68 (1H, m,
CH), 3.05 (2H, t, J ¼ 5.8 Hz, CH2N), 2.77 (1H, td, J ¼ 6.0, 15.8 Hz, CH2CH2N),
2.66 (1H, td, J ¼ 5.5, 15.8 Hz, CH2CH2N), 1.91–1.06 (10H, m, 5 ꢁ CH2) ppm. Anal.
calcd. for C18H26N2O3: C, 67.90; H, 8.23; N, 8.80. Found: C, 67.76; H, 8.11; N, 8.92.
N-Benzyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxamide
(3b). Yield: 0.69 g (75%), a white crystalline solid, mp 159–160 ꢀC (lit.[15] mp
1
160–162 ꢀC); H (CDCl3): d 7.56 (1H, br s, NH), 7.26–7.22 (5H, m, Ph), 7.07 (1H,
s, C6H2), 6.56 (1H, s, C6H2), 4.61 (1H, s, CHN), 3.83 (6H, s, 2 ꢁ OCH3), 3.08
(2H, m, CH2), 2.77–2.68 (2H, m, CH2CH2N), 20.4 (2H, s, CH2Ph) ppm. Anal. calcd.
for C19H22N2O3: C, 69.92; H, 6.79; N, 8.58. Found: C, 70.05; H, 6.87; N, 8.43.
N-(tert-Butyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxa-
mide (3c). Yield: 0.47 g (62%), a white crystalline solid, mp 139–142 ꢀC; 1H
(CDCl3): d 7.07 (1H, s, C6H2), 7.06 (1H, s, NH), 6.56 (1H, s, C6H2), 4.34 (1H, s,
CHN), 3.85 (3H, s, OCH3), 3.84 (3H, s, OCH3), 3.06 (2H, br s, CH2N), 2.80–2.62
(2H, m, CH2CH2N), 1.32 (9H, s, 3 ꢁ CH3) ppm. Anal. calcd. for C16H24N2O3: C,
65.73; H, 8.27; N, 9.58. Found: C, 65.89; H, 8.42; N, 9.39.
N-Cyclohexyl-1,2,3,4-tetrahydroisoquinoline-1-carboxamide (3d). Yield:
0.38g (61%), a white crystalline solid, mp 138–139 ꢀC; 1H (CDCl3): d 7.45–7.08
(4H, m, 4 ꢁ CH aromatic protons), 6.99 (1H, d, J ¼ 6.8 Hz, NH), 4.64 (1H, s,
CHN), 3.79–3.69 (1H, m, CH), 3.16 (1H, m, CH2N), 3.07 (1H, m, CH2N), 2.89
(1H, m, CH2CH2N), 2.78 (1H, m, CH2CH2N), 1.90–1.05 (10H, m, 5 ꢁ CH2) ppm.
Anal. calcd. for C16H22N2O: C, 74.38; H, 8.58; N, 10.84. Found: C, 74.51; H, 8.63;
N, 10.79.
N-Cyclohexyl-6,7-diethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxamide
1
(3e). Yield: 0.32 g (66%), a white crystalline solid, mp 147–148 ꢀC; H (CDCl3): d
7.00 (1H, s C6H2), 6.97 (1H, br s, NH), 6.57 (1H, s, C6H2), 4.52 (1H, s, CHN),
4.09–4.03 (4H, m, 2 ꢁ CH2CH3), 3.77–3.70 (1H, m, CH), 3.13–3.02 (2H, m,
CH2N), 2.81–2.74 (1H, m, CH2CH2N), 2.70–2.64 (1H, m, CH2CH2N), 1.89–1.03
(10H, m, 5 ꢁ CH2), 1.44–1.40 (6H, m, 2 ꢁ CH2CH3) ppm. Anal. calcd. for
C20H30N2O3: C, 69.33; H, 8.73; N, 8.09. Found: C, 69.57; H, 8.86; N, 7.89.
N-Cyclohexyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline-1-
carboxamide (3f). Yield: 0.38 g (74%), a white crystalline solid, mp 138–140 ꢀC;
1H (CDCl3): d 6.99 (1H, s, C6H2), 6.53 (1H, s, C6H2), 5.90 (1H, s, OCH2O), 5.89
(1H, s, OCH2O), 4.59 (1H, s, CHN), 3.71–3.69 (1H, m, CH), 3.20–3.05 (2H, m,
CH2N), 2.83–2.67 (2H, CH2CH2N), 1.88–1.09 (5 ꢁ CH2) ppm. Anal. calcd. for
C17H22N2O3: C, 67.53; H, 7.33; N, 9.26. Found: C, 67.41; H, 7.18; N, 9.39.
(1Rꢂ,3Rꢂ)-N-Cyclohexyl-6,7-dimethoxy-3-methyl-1,2,3,4-tetrahydroiso-
quinoline-1-carboxamide (7a). Yield: 0.46 g (56%), a white crystalline solid, mp
1
160–163 ꢀC; H (CDCl3): d 7.09 (1H, s, C6H2), 6.94 (1H, d, J ¼ 7.7 Hz, NH), 6.45