Process for preparing 3-acylamino-imidazo[1,2-a]pyridines

A process for preparing 3-acylamino imidazo[1,2-a]pyridines having the formula:

• 13
• wherein R is one or more units which can substitute for hydrogen ring atoms;
• R1 is C1-C12 linear, branched, or cyclic alkyl;
• C6-C10 substituted or unsubstituted aryl;
• C7-C12 substituted or unsubstituted alkylenearyl;
• R2 is C1-C12 linear, branched, or cyclic alkyl;
• C6-C10 substituted or unsubstituted aryl;
• C7-C12 substituted or unsubstituted alkylenearyl;
• C2-C10 substituted or unsubstituted heteroaryl;
• said process comprising the steps of:
• a.1) reacting an amine comprising resin with formaldehyde in the presence of a base to form an N-formylated resin;
• a.2) reacting said N-formylated resin with a dehydrating agent to form an isonitrile resin;
• b) reacting said isonitrile resin with an aldehyde having the formula R1CHO and a substituted or unsubstituted 2-aminopyridine in the presence of an acid catalyst to form a resin bound 2-substituted-3-aminoimidazo[1,2-a]pyridine;
• and
• c) cleaving said resin bound 2-substituted-3-aminoimidazo[1,2-a]pyridine substrate from said resin by reacting said substrate with an acyl halide having the formula R2COX;
• X is chlorine or bromine, to form said 3-acylamino imidazo[1 ,2-a]pyridine.

A process for preparing 3-acylamino imidazo[1,2-a]pyridines having the formula:

• 14
• wherein R is one or more units which can substitute for hydrogen ring atoms;
• R1 is C1-C12 linear, branched, or cyclic alkyl;
• C6-C10 substituted or unsubstituted aryl;
• C7-C12 substituted or unsubstituted alkylenearyl;
• R2 is C1-C12 linear, branched, or cyclic alkyl;
• C6-C10 substituted or unsubstituted aryl;
• C7-C12 substituted or unsubstituted alkylenearyl;
• C2-C10 substituted or unsubstituted heteroaryl;
• said process comprising the steps of:
• a.1) reacting Rink resin, said resin having the formula:
• 15
• with formaldehyde to form an N-formylated resin having the formula:
• 16
• a.2) dehydrating said N-formylated resin with a dehydrating agent to form an isonitrile resin having the formula:
• 17
• a) reacting said isonitrile resin with an aldehyde having the formula R1CHO and a substituted or unsubstituted 2-aminopyridine having the formula:
• 18
• to form a resin bound 2-substituted-3-aminoimidazo[1,2-a]pyridine having the formula:
• 19
• b) reacting said 2-substituted-3-aminoimidazo[1 ,2-a]pyridine with an acyl chloride having the formula R2COCl to form said 3-acylamino imidazo[1,2-a]pyridine.

A process for preparing 3-acylamino imidazo[1,2-a]pyridines having the formula:

• 20
• wherein R1 is selected from the group consisting of substituted or unsubstituted phenyl, benzyl, and 2-phenylethyl;
• R2 is selected from the group consisting of phenyl, furan-2-yl, and cyclopropyl;
• said process comprising the steps of:
• a) reacting Rink resin, said resin having the formula:
• 21
• with formaldehyde in the presence of a base to form a formylated Rink resin having the formula:
• 22
• b) reacting said formylated Rink resin with phosophorousoxychloride in the presence of a base to form an isonitrile resin having the formula:
• 23
• c) reacting said isonitrile resin with an aldehyde having the formula R1CHO and 2-aminopyridine in the presence of an acid catalyst to form a resin bound 2-substituted-3-aminoimidazo[1,2-a]pyridine substrate having the formula:
• 24
• d) cleaving said resin bound 2-substituted-3-aminoimidazo[1,2-a]pyridine substrate from said resin by reacting saidsubstrate with an acyl chloride selected from the group consisting of benzoyl chloride, 3-chlorobenzoyl chloride, furan-2-carbonyl chloride, and cyclopropanoyl chloride to form said 3-acylamino imidazo[1,2-a]pyridine.

A process for preparing 3-acylamino imidazo[1,2-a]pyridines having the formula:

• 25
• wherein R is one or more units which can substitute for hydrogen ring atoms;
• R1 is C1-C12 linear, branched, or cyclic alkyl;
• C6-C10 substituted or unsubstituted aryl;
• C7-C12 substituted or unsubstituted alkylenearyl;
• R2 is C1-C12 linear, branched, or cyclic alkyl;
• C6-C10 substituted or unsubstituted aryl;
• C7-C12 substituted or unsubstituted alkylenearyl;
• C2-C10 substituted or unsubstituted heteroaryl;
• said process comprising the steps of:
• a) reacting an isonitrile resin formed from Rink resin with an aldehyde having the formula R1CHO and a substituted or unsubstituted 2-aminopyridine having the formula:
• 26
• to form a resin bound 2-substituted-3-aminoimidazo[1,2-a]pyridine having the formula:
• 27
• c) reacting said 2-substituted-3-aminoimidazo[1,2-a]pyridine with an acyl chloride having the formula R2COCl to form said 3-acylamino imidazo[1,2-a]pyridine.