The unambiguous synthesis and NMR assignment of 4-alkoxy and 3-alkylquinazolines

…, Z Novák, K Palát, J Kuneš, J Pourová, M Pour

Index: Spulak, Marcel; Novak, Zdenek; Palat, Karel; Kunes, Jiri; Pourova, Jana; Pour, Milan Tetrahedron, 2013 , vol. 69, # 6 p. 1705 - 1711

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Citation Number: 4

Abstract

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, 13C NMR shifts of the–Z–CHn–(Z= O, N) fragment are necessary; resonances in the 45–55 ppm range are indicative of N3-alkylation. Treatment of 3, 4-dihydroquinazoline-4- one with p-TsCl afforded the N3-tosylated compound, whose reaction with an amine ...