Caffeine was first isolated from coffee in 1820 and tea in 1827 and was named after the French for coffee, cafe. The formula for caffeine is C8H10O2N4, GMM 194, and its structure is shown in Figure 1.
Its name is 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione or 1,3,7-trimethylxanthine. It is known as an alkaloid. An alkaloid is an n-containing compound of plant origin containing heterocyclic rings and one or more basic nitrogens. A heterocyclic ring is a ring containing atoms other than carbon. It belongs to the same chemical family as nicotine, morphine, codeine and cocaine. The essential amino acid tryptophan is also an alkaloid. A compound with a similar structure to caffeine is theobromine (which contains no bromine!), which is found in chocolate.
Theobromine does not contain bromine, despite its name. It is named after the tree theobroma cacao, the cacao tree from which chocolate is obtained. The name comes from the Greek theos (= god) + broma (= food), i.e. the food of the gods. The alkaloid theobromine was obtained from cocoa by adding the -ine ending used for alkaloids. (The apparent connection with bromine is thus fortuitous. However, the words broma and bromos are connected in Greek: bromos originally referred to the smell of food that had gone bad.) Cocoa contains around seven times more theobromine than caffeine.