A New Approach to Pyrazino[2,1-b]quinazolines and Pyrazino[1,2-a]thieno[3,2-d]pyrimidines

The reaction of [2-(chloromethyl)-4-oxo-3,4-dihydroquinazolin-3-yl]acetonitrile and 2-(chloromethyl)-3-(2-oxopropyl)quinazolin-4(3H)-one with aliphatic primary amines was shown to yield 2-alkyl-3-(alkylimino)-1,2,3,4-tetrahydro-6H-pyrazino[2,1-b]quinazolin-6-ones and 2-alkyl-3-methyl-1,2-dihydro-6H-pyrazino[2,1-b]quinazolin-6-ones, respectively. The starting materials were prepared by alkylation of 2-(chloromethyl)quinazolin-4(3H)-one with chloroacetonitrile or chloroacetone. Furthermore 2-alkyl-3-(alkylimino)-1,2,3,4,7,8,9,10-octahydro-6H-[1]benzothieno[2,3-d]pyrazino[1,2-a]pyrimidin-6-ones and 8-alkyl-2,3,7-trimethyl-8,9-dihydro-4H-pyrazino[1,2-a]thieno[2,3-d]pyrimidin-4-ones were obtained through the same sequence starting from the appropriate 2-(chloromethyl)thieno[2,3-d]pyrimidin-4(3H)-ones.

Kulik S. N.; Kobko A. S.; Tolmachev A. A.; Tverdokhlebov A. V.; Shishkin O. V.; Chernega A. N.
Synthesis 2007, 10, 1503-1508
DOI: 10.1055/s-2007-966025