What was the first artificial vitamin to be made?

It had been demonstrated that the addition of citrus fruits (C) to the diet would prevent the development of scurvy. In the 19th century it was shown that substituting unpolished for polished rice (B12) in a rice-based diet would prevent the development of beriberi.In 1906 the British biochemist Frederick Hopkins demonstrated that foods contained necessary "accessory factors" in addition to proteins, carbohydrates, fats, minerals, and water