The solution on acidification yields a yellow precipitate of this sulphide.
The product on acidification gives a compound C15H1205 ï¿½ H20 which is probably an oxy-methoxy-benzoyl benzoic acid.
With sodium ethylate in ethyl acetate solution it forms the sodium derivative of benzoyl acetone, from which benzoyl acetone, C6H5.CO.CH2.CO.CH3, can be obtained by acidification with acetic acid.
Oc 2 H 5 H Chï¿½C]](ONa) :CHï¿½000C2H5; and on acidification this last substance gives aceto-acetic ester.
Baeyer in 1890, by heating alizarin with fuming sulphuric acid for 24-48 hours at 35-40° C., obtained a product, which after treatment with caustic soda gave a sulphuric acid ester of quinalizarin, and this after acidification and boiling was converted into quinalizarin (Alizarin Bordeaux) or 220.127.116.11 tetra-oxyanthraquinone.