1,2,5-Oxadiazoles As Inhibitors Of Indoleamine 2,3- Dioxygenase

1 .- 174 . (canceled)

175 . A process for preparing a compound of Formula F15:

or a salt thereof, wherein R 2 is Cl, Br, CF 3 , CH 3 , or CN; R 3 is H or F; and n is 1 or 2, comprising:

a) reacting a compound of Formula F13:

or a salt thereof, wherein Pg 1 is an amino protecting group, with an amino deprotecting agent to afford a compound of Formula F14:

or a salt thereof; and

b) reacting said compound of Formula F14 with a base to afford said compound of Formula F15.

176 . The process of claim 175 , wherein R 2 is Br, R 3 is F, and n is 1.

177 . The process of claim 175 , wherein:

said Pg 1 is tert-butoxycarbonyl;

said amino deprotecting agent is trifluoroacetic acid or hydrochloric acid;

said reacting is performed in a solvent comprising dioxane and/or isopropanol; and

said base is sodium hydroxide.

178 . The process of claim 175 , wherein said compound of Formula F13 is obtained by treating a compound of Formula F12:

or a salt thereof, with Pg 1 -NH-sulfonyl chloride followed by treatment with an organic base to afford said compound of Formula F13.

179 . The process of claim 178 , wherein:

said Pg 1 comprises tert-butoxycarbonyl;

said treating is performed in dichloromethane; and

said organic base is triethylamine.

180 . The process of claim 178 , wherein said compound of Formula F12 is obtained by reducing a compound of Formula F11:

or a salt thereof.

181 . The process of claim 180 , wherein said reducing is carried out in the presence of sodium iodide, chlorotrimethylsilane, and methanol.

182 . The process of claim 180 , further comprising purifying said compound of Formula F12 by:

a) reacting said compound of Formula F12 with an amino protecting agent to afford a compound of Formula F12′:

or a salt thereof, wherein Pg 2 N is a protected amine;

b) purifying said compound of Formula F12′ to provide a purified compound of Formula F12′; and

c) reacting said purified compound of Formula F12′ with an amino deprotecting agent to provide a purified compound of Formula F12.

183 . The process of claim 182 , wherein:

said amino protecting agent is di-t-butyl dicarbonate;

said purifying is performed by chromatography on silica gel;

said amino deprotecting agent is hydrochloric acid; and

said reacting is performed in a solvent comprising dioxane and/or isopropanol.

184 . The process of claim 180 , wherein said compound of Formula F11 is obtained by treating a compound of Formula F10:

or a salt thereof, wherein L 1 is selected from alkylsulfonyl, haloalkylsulfonyl, and arylsulfonyl; with an azide reagent to afford said compound of Formula F11.

185 . The process of claim 184 , wherein:

L 1 is methanesulfonyl; and

said azide reagent is sodium azide.

186 . The process of claim 178 , wherein said compound of Formula F12 is obtained by reacting a compound of Formula F24:

or a salt thereof, wherein Pg 3 N is a protected amine; with an amino deprotecting agent to afford said compound of Formula F12.

187 . The process of claim 186 , wherein said protected amine is (C 6 H 5 ) 3 C—NH or (C 6 H 5 ) 2 C═N.

188 . The process of claim 186 , wherein said deprotecting agent comprises:

a) an organic acid; or

b) an organic acid and an organosilane.

189 . The process of claim 188 , wherein said organosilane is tri(isopropyl)silane.

190 . The process of claim 188 , wherein said organic acid is trifluoroacetic acid.

191 . The process of claim 186 , wherein said compound of Formula F24 is obtained by treating a compound of Formula F22:

or a salt thereof, with a compound of Formula F25:

or a salt thereof, wherein Pg 3 N is a protected amine; and a coupling reagent to provide said compound of Formula F24.

192 . The process of claim 191 , wherein said protected amine is (C 6 H 5 ) 3 C—NH or (C 6 H 5 ) 2 C═N.

193 . The process of claim 191 , wherein said compound of Formula F22 is obtained by

a) treating a compound of Formula F21:

or a salt thereof, with carbonyl diimidazole to afford a compound of Formula F26:

or a salt thereof; and

b) treating said compound of Formula F26 with trifluoroacetic anhydride to afford said compound of Formula F22.

194 . A process for preparing a compound of Formula F15:

or a salt thereof, wherein R 2 is Cl, Br, CF 3 , CH 3 , or CN; R 3 is H or F; and n is 1 or 2, comprising:

a) reacting a compound of Formula F12:

or a salt thereof, with sulfamide and an organic base to afford a compound of Formula F14:

or a salt thereof, and

b) reacting said compound of Formula F14, or a salt thereof, with a base to afford said compound of Formula F15.

195 . The process of claim 194 , wherein:

said organic base is pyridine;

said reacting of a compound of Formula F12 further comprises heating the reaction; and

said base is sodium hydroxide.

196 . A compound of Formula F12:

or a salt thereof, wherein R 2 is Cl, Br, CF 3 , CH 3 , or CN; R 3 is H or F; and n is 1 or 2.

197 . The compound of claim 196 , wherein R 2 is Br, R 3 is F, and n is 1.

198 . A compound of Formula F14:

or a salt thereof, wherein R 2 is Cl, Br, CF 3 , CH 3 , or CN; R 3 is H or F; and n is 1 or 2.

199 . The compound of claim 198 , wherein R 2 is Br, R 3 is F, and n is 1.