The new quinoline heterocycle would then be formed by combining this amine with the aldehyde produced in the tryptamine side-chain cleavage, giving cinchonidinone. For the last step, hydroxylation and methylation gives quinine. Catalysis
Quinine and other Cinchona alkaloids can be used as catalysts for stereoselective reactions in organic synthesis. : Table 3B Plate 560  For example, the quinine-catalyzed Michael addition of a malononitrile to α,β-enones gives a high degree of sterechemical control. History
Quinine was used as a muscle relaxant by the Quechua people, who are indigenous to Peru, Bolivia and Ecuador, to halt shivering. The Quechua would mix the ground bark of cinchona trees with sweetened water to offset the barks bitter taste, thus producing something similar to tonic water.Spanish Jesuit missionaries were the first to bring cinchona to Europe. The Spanish had observed the Quechuas use of cinchona and were aware of the medicinal properties of cinchona bark by the 1570s or earlier:  Nicolás Monardes (1571) and Juan Fragoso (1572) both described a tree, which was subsequently identified as the cinchona tree, whose bark was used to produce a drink to treat diarrhea. Quinine has been used in unextracted form by Europeans since at least the early 17th century.A popular story of how it was brought to Europe by the Countess of Chinchon was debunked by medical historian Alec Haggis around 1941. During the 17th century, malaria was endemic to the swamps and marshes surrounding the city of Rome. It had caused the deaths of several popes, many cardinals and countless common Roman citizens.
Most of the Catholic priests trained in Rome had seen malaria patients and were familiar with the shivering brought on by the febrile phase of the disease. The Jesuit Agostino Salumbrino (1564–1642), an apothecary by training who lived in Lima (now in present-day Peru), observed the Quechua using the bark of the cinchona tree to treat such shivering. While its effect in treating malaria (and malaria-induced shivering) was unrelated to its effect in controlling shivering from rigors, it was a successful medicine against malaria. At the first opportunity, Salumbrino sent a small quantity to Rome for testing as a malaria treatment. In the years that followed, cinchona bark, known as Jesuits bark or Peruvian bark, became one of the most valuable commodities shipped from Peru to Europe. When King Charles II was cured of malaria at the end of the 17th Century with quinine, it became popular in London. It remained the antimalarial drug of choice until the 1940s, when other drugs took over.The form of quinine most effective in treating malaria was found by Charles Marie de La Condamine in 1737. In 1820, French researchers Pierre Joseph Pelletier and Joseph Bienaimé Caventou first isolated quinine from the bark of a tree in the genus Cinchona – probably Cinchona pubescens – and subsequently named the substance. The name was derived from the original Quechua (Inca) word for the cinchona tree bark, quina or quina-quina, which means "bark of bark" or "holy bark".