The action of methyl, ethyl, and n-propyl alcohols on diazo compounds has been well studied by the above authors, and it has been shown that the first two at ordinary pressures give the alkoxy reaction either in whole or in part; n-propyl alcohol gives the hydrogen reaction only. Also the first two give the hydrogen reaction in the presence of zinc dust or sodium carbonate, but in these cases form salts of the acid. On account of its rarity n-propyl alcohol was not used, but n-butyl alcohol which is available in large quantities and in a pure condition was employed. Recent advances in fermentation as applied to organic chemistry have made this substance easily obtainable as a byproduct in the production of acetone which was needed in large amounts during the late war. Its use was found to be successful; it boils at 117 and so can be easily distilled off after decomposition has been effected without a great increase in temperature above the boiling point of water, which increase Griffin (loc. cit.) showed to cause carbonization. For this reason i-amyl alcohol although available was not considered,--also higher alcohols because of this fact and because of their rarity.
Of the four amino toluene sulphonic acids theoretically possible in which the sulphonic acid group is in the meta position in reference to the methyl group only two are commonly known, No. 1, and No. 2.
CH_{ 3} CH_{ 3} CH_{ 3} CH_{ 3} / \ / \ / \ / \ / \ / \ / \ / \ / \NH_{ 2} / \ / \NH_{ 2} / \ | | | | | | | | | | | | | | | | HSO_{ 3} \ / \ / HSO_{ 3} \ / NH_{ 2} \ / HSO_{ 3} \ / \ / \ / \ / \ / \ / \ / \ / NH_{ 2}
Methods of preparing No. 1 and No. 2 were found but without details, so a method had to be worked out to obtain them easily and in good yield. After a little experimenting No. 1, or ortho toluidine sulphonic acid was readily obtained in good yield and in a fairly pure condition. No. 2, or para toluidine meta sulphonic acid was obtained in only a ten per cent yield and by means of a much more difficult method of procedure. The preparation of this acid was undertaken first and consumed a long time; Griffin did his work starting with this acid and I hoped to get as far as he did earlier. It was then available in the market as was the ortho toluidine sulphonic acid, but now neither are available.