Patent ID: 6891046

Claim:
A process for preparing a polypyrrolinone having the formula (38): wherein: R is independently selected from a group consisting of a straight C 1 -C 6 alkyl, a branched C 3 -C 7 alkyl, C 3 -C 7 cycloalkyl, a straight C 1 -C 6 alkenyl, a branched C 3 -C 7 alkenyl, C 1 -C 4 hydroxyalkyl, C 1 -C 4 thioalkyl, C 1 -C 4 methylthioalkyl, —(CH 2 ) o N(R 5 ) 2 , —(CH 2 ) o CO 2 H, —(CH 2 ) o CON(R 5 ) 2 , heteroaryl, phenyl optionally substituted with one to three hydroxyl, C 1 -C 8 alkoxy, halo, nitro, or cyano groups, benzyl optionally substituted with one to three hydroxyl, C 1 -C 8 alkoxy, halo, nitro or cyano groups; R 1 is hydrogen, hydroxyl, C 1 -C 8 alkoxy, amino or alkoxycarbonyl-protected amino; R 2 is R, carboxyl, a carbonyl linked to a solid support or alkoxycarbonyl; R 3 is R or hydrogen; R 4 is R or (46); R 5 is hydrogen or C 1 -C 8 alkyl; n is 0 to 3; o is 1 to 4; comprising the steps: (a) reacting an α-amino-α-substituted-1,4-dioxo compound (39), optionally with an alkoxycarbonyl protecting group, with a 2-substituted-2-aminovalerolactone, trimethylorthoformate, optionally in the presence of a solvent, to produce imine (40) wherein: R 6 is an amino protecting group, R 7 is a C 1 -C 4 alkoxy or a carboxyl or carbamido linked to a solid support, or R 6 and R 7 together form a pyrrolinone ring; (b) cyclizing (40) by forming metalloimine carbanion with base optionally in the presence of a crown ether to form a pyrrolinone (41); (c) oxidizing the primary alcohol to the corresponding aldehyde; (d) repeating steps (a)-(c)m times to produce polypyrrolinone (42); (e) terminating the synthesis by repeating steps (a) through (b) using α-substituted amino ester in (f) place of the valerolactone in step (a) to yield (43).