No abstract

3‐Nitroaniline is 40 times and 3‐cyanoaniline 25 times as sweet as cane sugar. The taste of their derivatives, the 1‐alkoxy‐ and 1‐halogeno‐2‐amino‐4‐nitrobenzenes, which are very sweet, are now compared with those of the 1‐alkoxy and 1‐halogeno‐2‐amino‐4‐cyanobenzenes, which are also very sweet substances. The sweet taste diminishes when the nitro group is replaced by the cyano group. When the cyano group is hydrolysed to amido the sweet taste disappears.

Nitraniline is 40 times 2 ) and m-aminobenzonitrile 25 times as sweet as cane sugar. Both are volatile in steam, Replacement of the NO, group by CN reduces the sweet taste by a third. Hydrolysis of the C N to CONH, causes the sweet taste and also the volatility in steam to disappear. Tasteless compounds are also produced when the amino group is acylated.By condensing 3-aminobenzonitrile with I-chloro-2 : 4-dinitrobenzene there is produced 3'-cyano-2 : 4-dinitrodiphenylamine, which is tasteless and this on reduction with sodium disulphide gives tasteless 3'-cyano-2-amino-4-nitrodiphenylamine.In investigations on the taste of various compounds, it appears that mnlonic acid dihydrazide in the solid state, when placed upon the tip of the tongue, tastes very sweet 3 ) . From a close investigation it appears that in tests on solid substances on the tip of the tongue, the sweet taste is dependent on the size of the crystals and on the solubility in water. At first, one obtained the impression that cane sugar in powder form is sweeter .than coarse granulated sugar. Therefore, for the quantitative determination of the sweet taste, an aqueous solution of the substance under investigation was compared with an aqueous solution containing 1 % of cane sugar *). W h e n tested in this way, it was found that malonic acid dihydrazide, which tastes very sweet when placed on the tip of the tongue, is rather less sweet than cane sugar. Verkade, who has also followed the above method, has arrived at the same conclusion 5 ) .

The preparation of the N‐carbonic anhydrides and the carbomethoxy compounds of the following amino acids is described: glycine, valine, leucine, norleucine, phenylalanine, proline and cystine.