Scheme C l'apei'.\'337 achieved with ammonia solutions at lL 'l1" tPL" l 'illLll” L '.\ l\ ClU 'i\ 1 () U “(. f; compound Ila could be obtained in ot ')“rii _vicl< l., however. by using the standard procedure", ic by heating compound 8a with aqueous Z5"/11 animonia at 135 I95 '('in it pressure vessel. The combined elect ron-witlidrawiiig eltects of the two ring l\ l-atoms facilitate the nucleophilie substitution of the 4~ Cl atom in the 4.6-tlichloropyrimidine (9a) ...