| abstract |
A one-pot process for the preparation of pharmaceutically acceptable acid addition salts of 4,5,6,7-tetrahydrothieno(3,2-c) pyridine derivatives of formula (I) having antithrombotic activity, wherein R is hydrogen atom or CO2R2 group wherein R2 is C1-4 alkyl and R1 is C1-4 alkyl, C1-4 alkoxy, C1-4 acyloxy, hydroxy, nitro or halo, or racemic or enantiomeric isomer thereof. The process comprises reaction of N-(substituted benzyl)-2-(2-thienyl)ethylamine salt of formula VA wherein R and R1 are each as defined above and X is chloro or hydrogen sulfate group or racemic or enantiomeric isomer thereof, with paraformaldehyde in C1-6 alkanol in the presence of a mineral acid catalyst at 70 - 110 °C. |