Methods of making ureas and guanidines, including, terazosin, prazosin, doxazosin, tiodazosin, trimazosin, quinazosin, and bunazosin (exemplary of 2- substituted quinazoline compounds), and meobentine, and bethanidine and intermediates therefor
AssigneeBrantford Chemicals Inc.
InventorsKhashayar Karimian, Keshava Murthy, Darren Hall
Life of this patent
Estimating the term…
Abstract
Novel methods for the synthesis of substituted ureas and guanidines including Terazosin, Prazosin, Doxazosin, Tiodazosin, Trimazosin, Quinasin and Bunazosin (exemplary of 2-amino substituted Quinazolines), Meobentine and Bethanidine and novel intermediates suitable for use in such methods of synthesis are taught.
Claims20
The process of reacting compound (VIII) of the formula ##STR76## to give compound (VI) of the formula ##STR77## wherein Y is (i) hydrogen or wherein NY is (ii) a compound of the formula ##STR78## and when Y is H, compound (VIII) is reacted with compound (III) of the formula ##STR79## and when NY is (ii), compound (VIII) is reacted with NH.sub.3.
A process comprising reacting:
- compound (V') of the formula ##STR84## in the presence of NH.sub.3 to give compound (VI') of the formula ##STR85## wherein O--EP is a leaving group substitutable by --NH.sub.2 or an amine and wherein EP is selected from the group consisting of POCL.sub.3, PCl.sub.5, P.sub.2 O.sub.5, TsCl and wherein R is tetrahydrofuryl, furyl or 1-4-benzodioxan-2-yl.
A process comprising closing a ring in:
- compound (VI') of the formula ##STR88## to give compound (VII') of the formula ##STR89## wherein R is selected from furyl and 1,4-benzodioxan-2-yl.
Dependencies are inferred from the claim text.