Methods for preparing substituted imidazo[4,5-b]pyrazines

A method of producing a compound of Formula 201:

• wherein:
• R1 is selected from halogen, mesyloxy, p-nitrobenzenesulfonyloxy and tosyloxy;
• R4 is hydrogen;
• and
• R2 is selected from pentan-3-yl, heptan-4-yl, 4-methyl-1-morpholinopentan-2-yl, isobutyl, cyclohexyl, cyclopropyl, sec-butyl, tert-butyl, isopropyl, 1-hydroxybutan-2-yl, tetrahydro-2H-pyran-4-yl, 1-methoxybutan-2-yl, 1-aminobutan-2-yl and 1-morpholinobutan-2-yl;
• the method comprising:
• (a) treating a compound of Formula 101:
• wherein X is halogen;
• with an amine of formula R2—NH2 in a suitable solvent to produce a compound of Formula 102:
• and
• (b) treating the compound of Formula 102 with a di-activated carbonyl equivalent selected from carbonyl diimidazole, phosgene and triphosgene in a suitable solvent to produce the compound of Formula 201.