With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.91-21-4,1,2,3,4-Tetrahydroisoquinoline,as a common compound, the synthetic route is as follows.,91-21-4
All amines were purchased from Sigma-Aldrich (Merk) except7-nitro-1,2,3,4-tetrahydroisoquinoline 18 and 1-(2,4-dimethylphenyl)-N-methylmethanamine 19, the synthesis ofwhich is summarized below.On an ice bath (0 C), a 100-mL round bottom flask with 1.3 g(10 mmol) of 1,2,3,4-tetrahydroquinoline and 5mL of conc. H2SO4was allowed to stir for 10 min. To this solution, 1.1 g (10 mmol) ofKNO3 were added in small portions, taking care that the temperatureof the reaction did not rise above 5 C. The reactionwas stirredovernight and monitored by TLC (DCM/EtOH 90:10). The brownsolution was neutralized with a solution of diluted NH4OH untilpH 8 and the basic mixture was extracted with DCM (3 x 50 mL).The combined organic extracts were washed with brine (once),dried and filtered. The evaporation of the solvent affords a red oilwhich was dissolved in the minimum amount of abs. EtOH andcooled on an ice bath. The alcoholic solution was treated with2.5 mL of conc. HCl to affords a yellow precipitate of 7-nitro-1,2,3,4-tetrahydroisoquinoline 18, which was recrystallized from MeOH.Yellow solid; m.p.: 261-263 (260-262 C [57]); Yield: 32%; I.R.(nujol, cm-1): 3173; 1H NMR (CDCl3-TMS) delta: 1.86 (br s, 1H, NHdisapp. on D2O), 3.12 (t, 2H, H-4, J 8 Hz), 3.46 (t, 2H, H-3, J 8 Hz),4.37 (s, 2H, H-1), 7.36 (d, 1H, arom. H-5, J 12 Hz), 8.00 (m, 2H,arom. H-6 and H-8).
As the paragraph descriping shows that 91-21-4 is playing an increasingly important role.
Reference£º
Article; Zampieri, Daniele; Fortuna, Sara; Calabretti, Antonella; Romano, Maurizio; Menegazzi, Renzo; Schepmann, Dirk; Wuensch, Bernhard; Collina, Simona; Zanon, Davide; Mamolo, Maria Grazia; European Journal of Medicinal Chemistry; vol. 180; (2019); p. 268 – 282;,
Tetrahydroisoquinoline – Wikipedia
1,2,3,4-Tetrahydroisoquinoline | C9H11N – PubChem