申请人:Sridharan Ramasubramanian
公开号:US20060084806A1
公开(公告)日:2006-04-20
A process for the preparation of imidazo[1,2-a]pyridine derivatives of the formula I:
wherein R is hydrogen, halogen or a C
1
-C
4
alkyl group; R
1
and R
2
are independently hydrogen, a straight or branched C
1
-C
6
alkyl group which is unsubstituted or substituted by one or more halogen atoms, hydroxyl, N(C
1
-C
4
alkyl)
2
, carbamoyl or C
1
-C
4
alkoxy radicals, a C
1
-C
6
alkyl hydroxy group, a C
3
-C
6
cycloalkyl radical, a benzyl radical, a phenyl radical or R
1
and R
2
together with the nitrogen atom to which they are bonded are joined together to form a substituted or unsubstituted heterocyclic group optionally containing one or more additional heterocyclic atoms; and R
3
and R
4
are independently hydrogen, halogen or a C
1
-C
4
alkyl group, or a pharmaceutically acceptable salt thereof, the process comprising (a) reacting an imidazo[1,2-a]pyridine carboxylic acid of the formula II
wherein R, R
3
and R
4
have the aforestated meanings with a halogenating agent in the absence of a solvent to form an acid halide intermediate and (b) reacting the acid halide intermediate with an amine of the formula HNR
1
R
2
wherein R
1
and R
2
have the aforestated meanings to form the compound of formula I.
一种制备式I的咪唑[1,2-a]吡啶衍生物的过程:其中R为氢、卤素或C1-C4烷基;R1和R2独立为氢、直链或支链的未取代或取代一个或多个卤素原子、羟基、N(C1-C4烷基)2、氨基甲酰基或C1-C4烷氧基基团的C1-C6烷基基团、C1-C6烷基羟基、C3-C6环烷基基团、苄基基团、苯基基团或R1和R2连同它们连接的氮原子一起形成一个取代或未取代的杂环基团,该基团可选地含有一个或多个额外的杂环原子;R3和R4独立为氢、卤素或C1-C4烷基,或其药学上可接受的盐,该过程包括(a)在无溶剂的情况下将式II的咪唑[1,2-a]吡啶羧酸(其中R,R3和R4具有上述含义)与卤代试剂反应以形成酸卤中间体,和(b)将酸卤中间体与式HNR1R2的胺(其中R1和R2具有上述含义)反应以形成式I的化合物。