If you want the chemistry without the copyright violation, searching for "Shulgin PiHKAL Part 2 online" gives you the data without the PDF.
Alexander Shulgin is often called the "Godfather of Ecstasy" because he introduced MDMA to psychologists in the late 1970s, recognizing its profound therapeutic potential long before it became a popular recreational drug. Ann Shulgin was a pioneer in her own right, practicing psychedelic-assisted therapy and focusing on shadow work and spiritual integration. pihkal pdf
These are 300+ MB scans of the original 1991 paperback. They are often crooked, have dark gutters (spine shadow), and are missing pages 12, 247, and 522 due to scanner errors. These are the worst experience for a reader. If you want the chemistry without the copyright