IMPROVED PREPARATION OF 1,2,5,6-TETRAHYDRO-3-CARBOALKOXYPYRIDINES SUCH AS ARECOLINE AND SALTS OF 1,2,5,6-TETRAHYDRO-3-CARBOALKOXYPYRIDINES AND ARECOLINE HYDROBROMIDE

摘要

A process is provided for the preparation of 1,2,5,6-tetrahydro-3- carboalkoxypyridines of formula (III) wherein R is a straight or cyclic substituted or unsubstituted alkyl chain h aving 1 to 6 carbon atoms, phenyl C1-6 alkyl, menthol or a derivative of menthol, or a derivative of camphor, and R' is an alkyl chain having 1 to 4 carbon atoms o r phenyl C1-6 alkyl comprising reacting an alkyl pyridinium salt of formula (I I) wherein R and R' are as defined above and X is a suitable leaving group with sodium triacetoxyborohydride in the presence of an acid.