Patent ID: 6608216
Filing Date: 2003-08-19
Classification: C07D

Abstract:
A process for the preparation of a compound having formula (I) wherein R1 is selected from the group consisting of alkenyl, alkyl, alkynyl and aryl; R2, R3 and R4 are each independently selected from the group consisting of hydrogen, alkoxy, alkenyl, alkyl, alkynyl, aryl and halogen; or R2 and R3 or R3 and R4 together with the carbon atoms to which they are attached, together form a ring wherein the ring is selected from the group consisting of aryl, cycloalkyl and heterocycle; R5 is selected from the group consisting of hydrogen, alkenyl, alkenyloxy, alkoxy, alkoxycarbonyloxy, alkoxysulfonyloxy, alkyl, alkylcarbonyloxy, alkylsulfonyloxy, alkynyl, alkynyloxy, aryl, arylalkoxy, arylalkoxycarbonyloxy, aryloxy, arylsulfonyloxy, haloalkoxy, haloalkylcarbonyloxy, haloalkylsulfonyloxy, halogen, heterocycle and (NRCRD)carbonyloxy wherein RC and RD are each independently selected from the group consisting of hydrogen and alkyl; and R6, R7, R8 and R9 are each independently selected from the group consisting of hydrogen, alkoxy, alkenyl, alkyl, alkynyl, aryl and halogen; or R6 and R7 or R7 and R8 or R8 and R9 together with the carbon atoms to which they are attached, together form a ring wherein the ring is selected from the group consisting of aryl, cycloalkyl and heterocycle; wherein said process comprises the steps of: (a) treating a compound of formula (Ia) with a base in a first solvent â€ƒwherein RA is a hydroxy protecting group and R1, R2, R3, R4, R6, R7, R8 and R9 are as defined above; (b) treating the product of step (a) with an electrophile to provide a compound of formula (Ib) â€ƒwherein RB is selected from the group consisting of alkoxycarbonyl, alkoxysulfonyl, alkenyl, alkyl, alkylcarbonyl, alkylsulfonyl, alkynyl, arylalkoxycarbonyl, arylalkyl, arylsulfonyl, haloalkyl, haloalkylcarbonyl, haloalkylsulfonyl and (NRCRD)carbonyl; and RA, RC, RD, R1, R2, R3, R4, R6, R7, R8 and R9 are as defined above; (c) treating the compound of formula (Ib) with a hydroxy deprotecting reagent in a second solvent to provide a compound of formula (Ic) â€ƒwherein RB, R1, R2, R3, R4, R6, R7, R8 and R9 are as defined above; and (d) treating the compound of formula (Ic) with an azo reagent and a phosphine reagent in a third solvent.