Both classes readily exchange the imide hydrogen for acid radicals, and give nitrosamines with nitrous acid.
NH 2, which may be considered as derived from the acid-amides by replacement of oxygen by the divalent imino (= NH) group. They may be prepared by the action of ammonia or amines on imide chorides, or on thiamides (0.
It is oxidized to pyridine by heating with concentrated sulphuric acid to 300° C., or with nitrobenzene to 250° C., or with silver acetate to 180° C. Being an imide it readily yields a nitroso derivative, and N-alkyl and acidyl derivatives.
Somewhat later, they found that it could be prepared from diazobenzene imide, provided a nitro group were present in the ortho or para position to the diazo group. The para-nitro compound is dropped slowly into a cold solution of one part of caustic potash in ten parts of absolute alcohol; the solution becomes dark red in colour and is then warmed for two days on the water bath.
Orthonitro-diazobenzene imide only yields 30%.