Diphenyl triketone hydrate

B. Diphenyl Triketone Hydrate A solution of 34.3 g. (0.42 mole) of fused sodium acetate in 142 cc. of hot glacial acetic acid is prepared in a i-l. round-bottomed flask 72.4 g. (0.19 mole) of dibenzoyldibromomethane is added, and the mixture is refluxed until the precipitation of sodium bromide ceases (one and one-half to two hours). The mixture is then cooled to room temperature and diluted with 150-200 cc. of water with constant shaking to dissolve the inorganic salt and to precipitate the triketone hydrate, which separates as a white, curdy mass (Note 4). This is separated by filtration, washed well with water, and dried in an oven at 60°. The melting point varies from 65 to 90°, depending upon the extent of dehydration that occurs during the drying operation. The yield is 41.5 g. (86 per cent of the theoretical amount based on the dibenzoyldibromomethane). 

Diphenyl triketone, 13, 38 Diphenyl triketone hydrate, 13, 39 Disulfide, 12, 76... 

C. Diphenyl Triketone The 41.5 g. (0.16 mole) of triketone hydrate is distilled in vacuum from a Claisen flask heated by means of a sand bath. A distilling flask is used as a receiver, and no condenser is necessary. The neck of the receiving flask must be warmed, however, to prevent clogging of the apparatus by crystallization of the distillate. The anhydrous triketone distils at i74-i76°/2 mm. as a reddish oil that solidifies to a light yellow, crystalline mass. This is dissolved in 70 cc. of hot ligroin (b.p. 90-120°) it separates on cooling in light yellow needles which melt at 68 70°. The yield is 35 g. (91 per cent of the theoretical amount based on the triketone hydrate 59 per cent based on the dibenzoylmethane) (Note 5). 

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