1963

This invention relates to a new pyrazolo-pyrimidines and a process for their preparation. More particularly the invention concerns hydro-pyrazolo (3,4-d) pyrimidines having the nucleus of the formula

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which contain at least one of the positions 4 and 6 an oxo group and are alkylated, oxyalkylated, e.g. oxyethylated or cycloalkylated at at leats one ring nitrogen atom, their tautomeric forms and salt thereof.

This invention relates to a novel powder aerosol system. More specifically, this invention relates to a novel powder aerosol formulation which enables at least 15 percent by wieght of active powder to be dispensed in a conventional aerosol bomb.