I synthesized an adduct using 4-nitrothiophenol with iminoquinone RA-0001351 for the purpose of obtaining the X-ray crystal structure. The reaction went smoothly and completed in 30 minutes, and the product was isolated pure in a decent yield.
To compare the reactivities of different nucleophiles towards RA-0001351, 4-nitrophenol and 4-nitroaniline were chosen to react with RA-0001351 under identical conditions used with 4-nitrothiophenol, representing oxygen and nitrogen nucleophiles, respectively. However, both reactions were much slower and not finished after overnight. The product isolated from the reaction with 4-nitrophenol kept decomposing after isolation. The product isolated in low yield from the reaction with 4-nitroaniline was presumably the one shown below by H NMR (not pure) but was also not very stable, showing decomposition in LCMS.
Then I used benzyl thiol to react with RA-0001351, presuming that the corresponding products from reactions using benzyl alcohol and benzyl amine would be more stable. Surprisingly, the reaction of RA-0001351 with benzyl thiol was even slower. I observed primarily decomposition and unreacted RA-0001351 as major components. I isolated an adduct in approximately 2% yield, with more than one benzylthiol added onto the iminoquinone (as indicated by H NMR, but not cleanly resolved). This product appeared pure on TLC with Rf ~0.4, but LCMS analysis showed impurities, likely due to decomposition during analysis on the LCMS column.
I have used up all the RA-0001351 that was on hand. I synthesized another 500 mg, now plan to attempt reactions with thiophenol, and explore other thiol nucleophiles if necessary.
I synthesized an adduct using 4-nitrothiophenol with iminoquinone RA-0001351 for the purpose of obtaining the X-ray crystal structure. The reaction went smoothly and completed in 30 minutes, and the product was isolated pure in a decent yield.
To compare the reactivities of different nucleophiles towards RA-0001351, 4-nitrophenol and 4-nitroaniline were chosen to react with RA-0001351 under identical conditions used with 4-nitrothiophenol, representing oxygen and nitrogen nucleophiles, respectively. However, both reactions were much slower and not finished after overnight. The product isolated from the reaction with 4-nitrophenol kept decomposing after isolation. The product isolated in low yield from the reaction with 4-nitroaniline was presumably the one shown below by H NMR (not pure) but was also not very stable, showing decomposition in LCMS.
Then I used benzyl thiol to react with RA-0001351, presuming that the corresponding products from reactions using benzyl alcohol and benzyl amine would be more stable. Surprisingly, the reaction of RA-0001351 with benzyl thiol was even slower. I observed primarily decomposition and unreacted RA-0001351 as major components. I isolated an adduct in approximately 2% yield, with more than one benzylthiol added onto the iminoquinone (as indicated by H NMR, but not cleanly resolved). This product appeared pure on TLC with Rf ~0.4, but LCMS analysis showed impurities, likely due to decomposition during analysis on the LCMS column.
I have used up all the RA-0001351 that was on hand. I synthesized another 500 mg, now plan to attempt reactions with thiophenol, and explore other thiol nucleophiles if necessary.