The crystal structure of 6-chloro-2-(N,N-dimethylaminomethyleneamino)-1-(pi
valoyloxymethyl)pteridin-4-one confirms that the reaction of pterin 8-oxide
with acetyl chloride in trifluoroacetic acid produces the 6-chloride, and
that the minor product from alkylation of 6-chloro-2-(N,N-dimethylaminometh
yleneamino)pteridin-4-one with chloromethyl pivaloate in dimethylformamide
with potassium carbonate, is N-1-alkylated and not N-8- or C-4-O-alkylated.