Uracil and its homologues may be obtained in many cases from the hydrouracils by the action of bromine, and subsequent elimination of the elements of hydrobromic acid; or by the condensation of aceto-acetic ester and related substances with urea, thiourea, guanidine, &c. Uracil, C4H402N2, crystallizes in colourless needles, is soluble in hot water and melts with decomposition at 335° C. Hydrouracil, C4H602N2, is obtained by the action of bromine and caustic alkalis on succinamide (H.
It crystallizes in needles and is soluble in water.
It crystallizes in needles which melt at 320° C. and is soluble in caustic alkalis.
Benzamide, C6H5ï¿½Conh2,, crystallizes in leaflets which melt at 130° C. It is prepared by the action of ammonium carbonate on benzoyl chloride.
It crystallizes in yellow needles which melt at T 7 T ° C., and are only sparingly soluble in alcohol.