A red coloration was developed with aqueous and alcoholic Femc chloride solution.
5-Hydroxy-4-pyrone-2-methylisothiouroniumChloride.-To a solution of 9.6 g. (0.06 mole) of chlorokojic acid in 100 ml. of absolute ethanol was added 4.6 g. (0.06 mole) of thiourea, and the mixture was refluxed with stirring for one and one-half hours, a crystalline precipitate forming after approximately fifteen minutes. The mixture was cooled to 1 5 O , filtered, washed with anhydrous ether and recrystallized twice from ethafol to give 6 g. (49.3% yield) of a product melting a t 155 .
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