Synthesis of 2-amino-6,7,8,9-tetrahydro-6-phenethyl-3H-pyrimido[4,5-e][1,4]diazepin-4(5H)-one: a model for a potential pyrimido[4,5-e][1,4]diazepine-based folate anti-tumor agent

Reductive cyclization of 2-{N-[(2-amino-4,6-dichloropyrimidin-5-yl)methyl]-N-phenethylamino}acetonitrile (5) with Raney nickel and hydrogen gave the chloropyrimido[4,5-e][1,4]diazepine 3 which could not be converted to 2 via an attempted nucleophilic aromatic substitution with hydroxide. The title compound (2) was prepared, however, by the reductive cyclization of 2-{N-[(2-amino-4-chloro-6-methoxypyrimidin-5-yl)methyl]-N-phenethylamino}acetonitrile (13) followed by treatment with trimethyliodosilane.

One pot synthesis of cis-bispyrimidodiazepinone derivatives via low-valent titanium reagent (TiCl4/Sm)

An efficient and convenient method for the preparation of cis-bispyrimidodiazepinone derivatives has been described. A variety of substrates can participate in the process with good yields, making this methodology suitable for library synthesis in drug discovery efforts. The mechanistic course of the reaction suggests the involvement of reduction, coupling which determine the products' configuration and cyclization by one-pot.

Synthesis of novel 8,9-dihydro-5H-pyrimido[4,5-e][1,4]diazepin-7(6H)-ones

Practical and efficient methods have been developed for the synthesis of 4,6,8,9-tetrasubstituted 8,9-dihydro-5H-pyrimido[4,5-e][1,4]diazepin-7(6H)-ones from 4,6-dicholoropyrimidine aldehyde, N-substituted amino acid esters, and amines in five steps. This synthetic strategy is based on suitably substituted pyrimidines as bis-electrophilic species reacting with various amines to construct the pyrimido[4,5-e][1,4]diazepine core with a strategically anchored functional group for further derivatization. The utility of this methodology was demonstrated through the preparation of a 33-membered library of representative 8,9-dihydro-5H-pyrimido[4,5-e][1,4]diazepin-7(6H)-ones in good to excellent yields.