Process for the preparation of imidazo [1,2-a] pyridines

DETAILED DESCRIPTION What is claimed is: 1.
A process for the preparation of a compound having the formula: ##STR6## which comprises treating a compound having the formula: ##STR7## wherein X is a halogen, loweralkoxy or loweralkylthio, with methyl chloroacetyl carbamate to form: ##STR8## which is treated with ammonia and then heated in order to form the desired product.
2.
The process of claim 1 wherein X is chlorine, bromine, methoxy or methylthio.
3.
The process of claim 2 wherein the heating step is carried out in the presence of methanol.
4.
A process for the preparation of a compound having the formula: ##STR9## which comprises treating a compound having the formula: ##STR10## wherein X is a halogen, loweralkoxy or loweralkylthio, with methylchloroacetylcarbamate to form: ##STR11## which is treated with ammonia and then heated in order to form: ##STR12## which is oxidized to the desired product.
5.
The process of claim 4 wherein X is chlorine, bromine, methoxy or methylthio.
6.
The process of claim 5 wherein the heating step is carried out in the presence of methanol.




Description:
SUMMARY OF THE INVENTION This invention is concerned with processes for the preparation of 2-(methoxycarbonylamino)-6-(phenylsulfinyl) imidazo [1,2-a] pyridine, which is an active anthelmintic agent.
The process involves the treatment of a 5-phenylsulfinyl pyridine which is substituted at the 2-position with a leaving group such as a halogen, a loweralkoxy or a loweralkylthio group, with methylchloroacetylcarbamate.
The quaternary intermediate thus formed is treated with ammonia, preferably in the presence of a protic solvent in order to form the desired product.
Thus it is an object of the present invention to described such processes for the preparation of the indicated compound.
A further object of this invention is to describe the preparation of the starting materials employed in these processes.
Still further objects will become apparent upon reading the following description.
The compound 2-(methoxycarbonylamino)-6-(phenylsulfinyl) imidazo [1,2-a] pyridine is depicted structurally as: ##STR1## and the imidazo [1,2-a] pyridines nucleus is numbered as follows: ##STR2## The process of this invention is depicted schematically in the following reaction: ##STR3## wherein X is a leaving group selected from a halogen, such as chlorine, bromine or iodine; loweralkoxy or loweralkylthio