Patent ID: 8846953

Claim:
A process for preparing a substituted 3-((pyrrol-2-yl)methylene)-2-pyrrolone of formula (I) or a salt thereof: comprising: a) reacting a compound of formula (II): or a compound of formula (V): with a compound of formula (III): to obtain the substituted 3-((pyrrol-2-yl)methylene)-2-pyrrolone of formula (I), wherein R 1 and R 4 are optionally and independently H, C 1 -C 8 alkyl, aryl, benzyl, heteroaryl, silyl; R 2 and R 3 are optionally and independently H, C 1 -C 8 alkyl, aryl, heteroaryl, or together form a substituted or unsubstituted ring; R independently is C 1 -C 8 alkyl, aryl, H or an oxygen-based substituent; R 5 is H, C 1 -C 8 alkyl, aryl, heteroaryl, or COR′ wherein R′ is H, C 1 -C 8 alkyl, aryl, heteroaryl, O—C 1 -C 8 alkyl, N,N-di-C 1 -C 8 alkyl, NH—C 1 -C 8 alkyl or N, N-diaryl; R 6 , R 7 , and R 8 independently are H, C 1 -C 8 alkyl, aryl, heteroaryl, silyl, COR″ wherein R″ is H, C 1 -C 8 alkyl, aryl, benzyl, heteroaryl, substituted or unsubstituted heterocyclic, OH, SH, NH 2 , O—C 1 -C 8 alkyl, NH—C 1 -C 12 alkyl, N,N-di-C 1 -C 12 alkyl, N,N-diaryl, N,N-dibenzyl, or S—C 1 -C 8 alkyl; and optionally where R 5 and R 6 together form a ring; and optionally where R 6 and R 7 together form a ring; and optionally where R 7 and R 8 together form a substituted or unsubstituted ring, and R 9 and R 10 are independently selected from C 1 -C 12 alkyl or silyl, or in the alternative, R 9 and R 10 form a ring together; X is Cl, Br, I, triflate (OTf), OP(O)Cl 2 OP(O)Br 2 OH, tosylate (TsO), mesylate (MsO), or R′″CO 2 , where R′″ is C 1 -C 8 alkyl, aryl or heteroaryl; and b) optionally reacting the substituted 3-((pyrrol-2-yl)methylene)-2-pyrrolone of formula (I) with a salt forming agent to obtain the salt thereof; wherein the reaction between the compound of formula (II) and the compound of formula (III) in the reacting step a) is conducted in the presence of a catalyst and in a solvent.