Synthesis of caffeine from theobromine: Bringing back an old experiment in a new setting

Caffeine is one of the most widely consumed, naturally occurring, mild, and central nervous system stimulants. Its synthesis, by the N-methylation (SN2 substitution) of theobromine is described as an experiment for the undergraduate organic chemistry laboratory. The N-methylation of theobromine is rapid and efficient and its progress is monitored by TLC using authentic standards. The undergraduate student also is able to observe the effect of temperature on the rate of the N-methylation reaction.