Furfural-Ubiquitous
Natural Product
I n this day of rising prices and tight budgets, wouldn't i t be gratifying to find a. chemical experiment that utilizes You doubt that this is possible?? Please reconsider, unless you are willing t o buy dead leaves from your neighbor's lawn, orange rinds from the garbage man, or peanut shells from the janitor after a ball game. These apparently useless botanical residues plus dozens of others can indeed be used as the starting point for an organic synthesis, the preparation of furfural (2-furaldehyde). Almost any plant material (I), even old labaratmy corks, will yield some furfurd when treated by a. very simple process, brief refluxing with acid followed by distillation. Being readily steam distillable, the desired product will be found in the distillate as a dilute aqueous solution. Even though present in less than ly' concentration, the furforal can be readily observed and identified by its ultraviolet spectrum and the formation of its 2,Gdinitrophenyl hydrazone. This bright red, solid derivative can be characterized by melting point ( 2 ) and Ri values from various tlc systems @). The following procedure has been found to be quitesatisf&ory. n reagent that costs nothing and is readily available?
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Place 1 or 2 e of finelv " chonoed raw meterid in a 25-ml flask cantainine 10 ml of 2M HCI. Reflux gently for 20 min using a water-cooled condenser. Collect 2 ml of distillate. Add 10 mg of distillate to 3.0 ml of water in a. cell, and obtain the ultraviolet spectrum; maximum absorbance occurs a t 277 mp (4). Add the remainder of the distillate to an equal volume of 2M HC1 saturated with 2,4dinitrophenylhydrazinefor preparing thederivative (6). The predominant product is the transisomer (8).
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I n our laborrutorv we have obtained furfural from manv. t w e s of citrus neelines. .. banana skins.. ..eourd rinds. corn
c h ~ WIIROHPI , stulks, dried lravei, W J W , rork, ~ U 41d1
