Synthetic and analytical studies on colour reagents-IX The reactions of phthaleinazo compounds with the alkaline earths.
Some new phthaleinazo compounds-o,o'-dihydroxyazo compounds-have been prepared by coupling chromotropic acid, R-acid, and 2-hydroxy-3-naphthoic acid with bis-diazotized diaminophthaleins. These compounds have been found to be very sensitive colour reagents for alkaline earths in alkaline media, and in particular, bis(chromotropeazo)phenolphthalein is the most sensitive yet found.
Kobatake
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Department of Chemistry Faculty of Science, Okayama University Tsushima, Okayama-shiJapan.
Iwachido
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Tôei
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