Patent ID: 6455698
Filing Date: 2002-09-24
Classification: A61P,C07D

Abstract:
A process for the preparation of a compound of formula comprisinga) reacting a compound of formula, â€ƒwith phosgene in the presence of an inorganic base; b) brominating the product of step a) above in a solution of AcOH/TFA; c) nitrating the product of step b) above with KNO3/H2SO4; d) treating the product of step c) above with an alcohol; e) reducing catalytically the product of step d) above with Raney Nickel and with hydrogen donating solvents under a hydrogen atmosphere in the presence of a base; f) treating the product of step e) above with an oxalic acid derivative in a polar solvent or an ethereal solvent; g) nitrating the product of step f) above with a nitrating mixture and isolating the product; and h) hydrolyzing the product of step g) above in the presence of a base in a water soluble solvent.