History of aspirin mid-eighteenth century. By the nineteenth century pharmacists were experimenting with and prescribing a variety of chemicals related to salicylic acid, the active component of willow extract. In 1853, chemist Charles Frédéric Gerhardt treated acetyl chloride with sodium salicylate to produce acetylsalicylic acid for the first time; in the second half of the nineteenth century, other academic chemists established the compound's chemical structure and devised more efficient methods of synthesis. In 1897, scientists at the drug and dye firm Bayer began investigating acetylsalicylic acid as a less-irritating replacement for standard common salicylate medicines, and identified a new way to synthesize it.
U Should've Known Better producers, which included Dallas Austin, production team Soulshock & Karlin, Bryan Michael Cox, and Rodney Jerkins and his Darkchild crew. Though she "had never thought about writing much" by then, her producers encouraged the singer to intensify her work on the "All Eyez on Me" album and to write and contribute own lyrics and ideas to the songs, one of which was the ballad "U Should've Known Better." Monica penned the song along with Harold Lilly and longtime contributor Jermaine Dupri, while production on the track was helmed by Dupri and Bryan Michael Cox. "U Should've Known Better" was mixed