title: Silica-supported polyphosphoric acid in the synthesis of 4-substituted tetrahydroisoquinoline derivatives.
abstract: We report herein an application of an α-amidoalkylation reaction, as an alternative efficient synthesis of 4-aryl- and 4-methyl-1,2,3,4-tetrahydroisoquinoline derivatives. The amides required for this purpose would result from reaction of aminoacetaldehyde dimethylacetal with different substituted benzenes in polyphosphoric acid, followed by acylation of the obtained amines with different acid chlorides or sulfochlorides. We compared the cyclisation step using conventional (milieu of acetic-trifluoracetic acid = 4:1) and solid supported reagents (SiO₂/PPA), as recovered, regenerated and reused without loss of its activity catalyst. We found that in comparison to conventional methods, the yields of the reaction are greater and the reaction time is shorter.
authors: Department of Organic Chemistry, University of Plovdiv, 24 Tzar Assen Str., 4000 Plovdiv, Bulgaria.
authors: Stanimir
authors: S
authors: Manolov
authors: Stoyanka
authors: S
authors: Nikolova
authors: Iliyan
authors: I
authors: Ivanov
mesh_terms: D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry; D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D044005:Tetrahydroisoquinolines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000577:Amides; D000588:Amines; D010756:Phosphoric Acids; D011108:Polymers; D044005:Tetrahydroisoquinolines; D012822:Silicon Dioxide; C047269:polyphosphoric acid
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