Synthesis of some N-methyl-1,2,3,4-tetrahydroisoquinolines by Friedel–Crafts cyclisation using benzotriazole auxiliary

Crystal structure of 2-methyl-1,2,3,4-tetrahydroisoquinoline trihydrate

“…The pure amine is known from the literature and the measured analytical NMR and MS data correspond to the reported data (Locher & Peerzada, 1999). 1 H NMR (CDCl 3 , 400 MHz): (ppm) 2.48 (3H, s, NCH 3 ), 2.72 (2H, t, NCH 2 CH 2 ), 2.95 (2H, t, NCH 2 CH 2 ), 3.61 (2H, s, NCH 2 C ar , 7.02-7.04 (1H, m, CH ar ), 7.11-7.15 (3H, m, CH ar ).…”

Synthesis of Some Bis(n-1,2,3,4-Tetrahydroisoquinolinyl) Methanes Using Benzotriazole as Auxiliary

“…A ratio of 1:200 yields the corresponding bis-product 4d after stirring for 30h at approx. 80 °C; under the same conditions, but in a ratio of 1:40, the corresponding Nbenzotriazol-l-ylmethyl-5,7-dichloro-l,2,3,4-tetrahydroisoquinoline 5d is obtained (9) Compound 5d has previously not been accessible by cyclisation of 3d with AICI3, a milder FriedelCrafts catalyst (8). A similar reaction pattern is also observed for the other deactivated compounds (3b,c as well as 3e-g), which all yield the corresponding N-benzotriazol-l-ylmethyl-1,2,3,4-tetrahydroisoquinolines when reacted for 2h at 4 °C, followed by 2h stirring at room temperature in a ratio starting material to H2SO4 of 1:45 (9).…”

“…The corresponding iV,A^-bis(benzotriazol-l-ylmethyl)phenyIethylamines 3a-h are obtained as crystalline products and recrystallised from EtOH. Mp and spectral data for compounds 3a-h were already reported elsewhere (8,9).…”

Isolation and X-ray Crystal Structure of Tetrahydroisoquinoline Alkaloids from Calycotome Villosa Subsp. intermedias

“…These natural alkaloids are generally optically active compounds possessing important clinical applications such as analgesics, antihypertensives, smooth or skeletal muscle relaxants, antispasmodics, antitussives, antimalarials, narcotics and antipyretics [5]. It is worth noting that 1-substituted-THIQs, in which C-1 is a quaternary stereogenic centre, have been reported to display very interesting biological and pharmacological properties [3,6,7]. For instance, 1-methyl-and 1-phenyltetrahydroisoquinoline are involved in the treatment of Parkinson's and other nervous system diseases [8][9][10].…”