A solution of
110 g. (0.52 mole) of sodium 2-bromoethanesulfonate (p. 558) in about
2 l. (28 moles) of concentrated aqueous ammonia (sp. gr. 0.9) is allowed to stand for five to seven days (Note
1) and is then evaporated to dryness. The last of the water is removed by heating on a
steam bath. The residue is dissolved in the minimum quantity of hot water (about 500 cc.) and, if necessary, treated with
5 g. of Norite. The colorless solution is concentrated to 65–70 cc., and
250 cc. of 95 per cent alcohol is added. In a short time
taurine mixed with some
sodium bromide separates. When crystallization is complete, the crude
taurine is collected on a filter and recrystallized by dissolving in 100 cc. of hot water and then adding to the solution enough
95 per cent ethyl alcohol (about 500 cc.) to give a final concentration of
80 per cent of alcohol. The
taurine which separates is usually free from bromides. However, occasional runs must be recrystallized four or five times to remove all the
sodium bromide. The yield of pure
taurine (Note
2) is
31–36 g. (
48–55 per cent of the theoretical amount).