May, 1948 REACTION OF AZLACTONES WITH SECONDARY AMINES 1769 ... John C. Brantley using a Model D Beckman spectro- photometer with 95% ethanolic solutions of the white (5.22 mg. per liter of solution) and yellow (12.1 mg. per liter of solution) forms. Ozonolysis.-Five and five-tenths grams (0.025 mole) of yellow N,N'-diacetyltetrahydro-4,4 '-dipyridyl dis- solved in 40 ml. of glacial acetic acid was ozonized for forty-eight hours at 20" with 3% ozone flowing ...