Lapachol.(CHAPTER II. The Naphthoquinone Group.) (Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

This colouring matter has been obtained from the wood of the Lapacho tree, from Greenheart wood, and also from Bethaberra wood. It was from the first-named that Arnaudon (Comptes rend., 1858, 46, 1154) originally obtained it by extracting the wood with alcohol, and recrystallising the product from a mixture of alcohol and ether. Stein (J. f. pr. Chem., 99, 1) showed that the same colouring matter was present in Greenheart wood, whilst Green and Hooker (Amer. Chem. Jour., 11, 267) obtained it from Bethaberra wood.

According to Paternò (Gazetta, 12, 337; 21, 374) the colouring matter is best extracted from the wood by means of soda solution (1 gram soda crystals in 16 grams water for 20 grams finely divided wood), the product being precipitated from the combined extracts by means of hydrochloric acid, purified by extraction with barium hydroxide solution and reprecipitation with acid. The product thus obtained when recrystallised from benzene is readily obtained in a pure condition.