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Acetylation and crystallization from methanol gave tigogenin acetate, m. p. and mixed m. p. 204°.

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Procedures have been developed for the synthesis of 5,6-diamino-2,4-dihydroxypyrimidine and 4-hydroxy-2,5,6-triaminopyrimidine bisulfite in appreciably better yields and involving fewer isolations of intermediate products than previously reported.2. These compounds have been condensed with several dicarbonyl compounds to yield pyrimido [4,5-b]pyrazines symmetrically substituted in the 6-and 7positions.3. Ultraviolet absorption spectra of alkaline solutions of the compounds have been measured. Ithaca, X. Y.