This work depends on synthesis of some new quinoxaline derivatives via a simple methods from the key intermediates; 6-bromo-2,3-dichloroquinoxaline (201) and 6-bromo-3-methylquinoxalin-2(1H)-one (227), also studying the chemical reactivity of these compounds towards some nucleophilic reagents to give new substituted and condensed quinoxaline derivatives. The first starting material, 6-bromo-2,3-dichloroquinoxaline (201) was subjected to some nucleophilic reagents to study the effect of bromine atom on the reactivity of two chlorine atoms. Thus, compound (201) was treated with one or two moles of hydrazine hydrate to produce various hydrazinyl derivatives (202b and 208); (Scheme 77, 79). Also, compound (202b) was reacted with one mole of nitrous acid to form monotetrazolo derivative (203); (Scheme 77), while reaction of compound (208) with two mole of the same reagent produced ditetrazolo derivative (210). Also, compound (210) was formed by another method via reaction of compound (201) with two moles of sodium azide; (Scheme 79). Furthermore, aminotetrazoloquinoxalines (204a,b) were produced via reaction of compound (203) with amines; (Scheme 77). In addition, the hydrazinyl compounds (202b and 208) were subjected to reaction with acetylacetone to....