Patent ID: 7605275

Claim:
A process for preparing Compound 1: said process comprising the steps of: (a) cyclizing Compound 2 in a first solvent at an elevated temperature where R 5 and R 6 are each independently selected from the group consisting of II, alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, alkylaryl, arylalkyl, heterocyclic and heteroaryl groups, or R 5 and R 6 , together with the nitrogen to which they are attached, for a 3- to 6-membered heterocyclic compound containing 1-4 heteroatoms, to produce a first mixture of exo isomers said isomers having a trans-[5,6]-ring junction: and endo isomers: (b) epimerizing said trans-[5,6]-ring-junction in Compound 29 by treating said first mixture with a first base to produce a second mixture comprising cis-[5,6]-ring-junction-nitro-α isomer and cis-[5,6]-ring-junction-nitro-β isomer of Compound 30: and (c) treating said second mixture with a second solvent, causing said α-isomer of Compound 30 to precipitate to produce Compound 1.