. "0040-4020" . "[634F7CE1FA49]" . . . . "The unambiguous synthesis and NMR assignment of 4-alkoxy and 3-alkylquinazolines" . "Contrary to a number of reports, alkylations of the privileged 3,4-dihydroquinazoline scaffold provide N3-alkylated products, and not 4-alkoxyquinazolines. To correctly assign the structure, C-13 NMR shifts of the -Z-CHn- (Z=O, N) fragment are necessary; resonances in the 45-55 ppm range are indicative of N3-allcylation. Treatment of 3,4-dihydroquinazoline-4-one with p-TsCl afforded the N3-tosylated compound, whose reaction with an amine yielded the corresponding N3-alkyl derivative. A mechanism corroborated by N-15-labeling involving pyrimidine ring opening and recyclisation is proposed. Finally, the unambiguous preparation of 4-alkoxyquinazolines is described via treatment of 3,4-dihydroquinazoline-4-ones with PCl5 followed by an alkoxide." . "000315613000004" . "Pal\u00E1t, Karel" . "http://www.sciencedirect.com/science/article/pii/S004040201201873X" . "The unambiguous synthesis and NMR assignment of 4-alkoxy and 3-alkylquinazolines"@en . . "Contrary to a number of reports, alkylations of the privileged 3,4-dihydroquinazoline scaffold provide N3-alkylated products, and not 4-alkoxyquinazolines. To correctly assign the structure, C-13 NMR shifts of the -Z-CHn- (Z=O, N) fragment are necessary; resonances in the 45-55 ppm range are indicative of N3-allcylation. Treatment of 3,4-dihydroquinazoline-4-one with p-TsCl afforded the N3-tosylated compound, whose reaction with an amine yielded the corresponding N3-alkyl derivative. A mechanism corroborated by N-15-labeling involving pyrimidine ring opening and recyclisation is proposed. Finally, the unambiguous preparation of 4-alkoxyquinazolines is described via treatment of 3,4-dihydroquinazoline-4-ones with PCl5 followed by an alkoxide."@en . . . . . "6" . . "112535" . . "6"^^ . "RIV/00216208:11160/13:10145815!RIV14-GA0-11160___" . "Nov\u00E1k, Zden\u011Bk" . "6"^^ . . "RIV/00216208:11160/13:10145815" . . "7"^^ . . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . "\u0160pul\u00E1k, Marcel" . . . "10.1016/j.tet.2012.12.031" . . . "The unambiguous synthesis and NMR assignment of 4-alkoxy and 3-alkylquinazolines" . "Pour, Milan" . "N3-alkylation; O-alkylation; NMR; Quinazoline"@en . "The unambiguous synthesis and NMR assignment of 4-alkoxy and 3-alkylquinazolines"@en . "Kune\u0161, Ji\u0159\u00ED" . . "11160" . . "Pourov\u00E1, Jana" . "I, P(GAP207/10/2048), S" . . . "Tetrahedron" . . "69" . .