The First Tandem Acetalization/5-<i>exo</i>-<i>dig</i> Cyclization of 6-Phenylethynylpyrimidine-5-carbaldehydes: Efficient Synthesis of 5-Alkoxy-(7<i>Z</i>)-7-benzylidene-5<i>,</i>7<i>-</i>dihydrofuro[3,4-<i>d</i>]pyrimidines
The first example of catalyst-free tandem acetalization/5-exo-dig cyclization reactions of 6-phenylethynylpyrimidine-5-carbaldehydes is presented. Efficient novel synthesis of 5,7-dihydrofuro[3,4-d]pyrimidine core is described.
Study on the cyclization of 6-arylethynylpyrimidine-5-carbaldehydes with tert-butylamine: microwave versus thermal preparation of pyrido[4,3-d]pyrimidines
Thermal and microwave initiated cyclization of 2,4-disubstituted 6-arylethynylpyrimidine-5-carbaldehydes with tert-butylamine has been studied. A novel high-yielding preparation of 2,4-disubstituted 7-arylpyrido[4,3-d]pyrimidines has been developed. The intermediate compounds were isolated and possible mechanism of the reactions is discussed. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.
Kaminskas; Dailide; Tumkevicius, Polish Journal of Chemistry, 2002, vol. 76, # 5, p. 725 - 728