Furoin was used as fluorogenic reagent for the selective and sensitive liquid chromatographic determination of various guanidines.
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2,2'-Furoin is prepared by the condensation of furfural with benzoin under the catalysis of potassium cyanide. 8L of water, 3L of ethanol, and 4kg of furfural were heated to 60-70°C on a water bath, and a solution of 200g potassium cyanide dissolved in 600Chemicalbookml of water was slowly added under stirring. The reaction exotherm automatically heated up to 80-90 ° C, and crystals were precipitated later. After standing, filter, wash the crystals with water and methanol until the washing is colorless, and recrystallize with ethanol, which is the finished product of bran coupler.
Purification Methods
It crystallises from MeOH (charcoal) and distils in a vacuum. [Hartman & Dickey J Am Chem Soc 55 1228 1933.] The (-)-enantiomer crystallises from toluene or EtOH with m 131-131o, and [] 20 -4.9o (dioxane) [Neuberg et al. Arch Biochem 1 393 1943, Beilstein 19 H 204, 19 I 710, 19 II 224, 19 III/IV 2543.]
