Synthesis and purification procedures of heteroaryl compounds

A process for preparing a compound of formula (II): Formula ** ** process comprising contacting a compound of formula (VI) with R1 ** ** Formula-Y in a solvent in the presence of a palladium catalyst selected from dichloro [1,1'-bis (ditercbutilfosfino) ferrocene] palladium and dichlorobis (p-dimetilaminofenildibutilfosfina) palladium (II), wherein said contacting occurs under conditions suitable to yield a compound of formula (II) wherein: X is halogen, B (oR +) 2 or Sn (R ++) 3; Y is halogen, triflate, B (OR +) 2 or Sn (R ++) 3; wherein a) when X is halogen, then Y is B (OR +) 2 or Sn (R ++) 3; b) when Y is halogen or triflate, then X is B (OR +) 2 or Sn (R ++) 3; wherein each R + is independently hydrogen or C1-3alkyl unsubstituted or substituted, or each R +, together with the boron atom and the atoms to which they are attached, form a cyclic boronate; and R ++ is a C1-3alkyl; and wherein: R1 is C1-8alkyl substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl or substituted or unsubstituted heterocyclylalkyl, substituted or unsubstituted; R2 is H, C1-8 alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted, substituted or unsubstituted heterocyclylalkyl, substituted or unsubstituted aralkyl or substituted or unsubstituted cycloalkylalkyl; R3 is H, or C1-8alkyl substituted or unsubstituted; provided that the compound of formula (II) is not 7- (4-hydroxyphenyl) -1- (3-methoxybenzyl) -3,4-dihydropyrazino [2,3- b] pyrazin-2 (1H) -one.