48 Proceedings of the Royal Irish Academy. 



two recrystallizations from absolute alcohol, the compound was obtained in 

 glistening white needles, which melted sharply at l-J3-5-134'o° C. 



Dehydro cateehin tetramethyl ether is easily soluble in benzene and 

 chloroform, sparingly soluble in ether, ligroin, and cold absolute alcol>ol. Its 

 solution in alcohol does not give any colouration with a solution of ferric 

 chloride. It dissolves in cold concentrated sulphuric acid, forming a deep 

 orange solution. The yield of the pui-e compound was 4 giams. 

 On analysis : — 



0-1666 grams of the substance gave 0-4:238 grams of CO, and 0092i 



grams of H-^O, corresponding to C 69.37, H 6-21. 

 C19H20O5 requires C 6948, H 6-14. 



The action of h-omine on dehydro cateehin tetramethyl ether. 



66 grams of pure debydro cateehin tetramethyl ether were dissolved in 

 60 c.c. of chlorofoi-m at room temperature, and to this solution 32 c.c. of a 

 second chloroform solution containing 3-2 grams of bromine were added. 

 Fumes of hydrogen bromide were immediately evolved, the solution simul- 

 taneously assuming a wine-red tint. After about an hour the separation from 

 the solution of a red crystalline precipitate was complete. The solid product 

 was filtered off on the pump, allowed to stand for a few hours on a jiorous 

 plat«, and finally kept for two days in a vacuum desiccator over powdered 

 caustic soda. Acciu-ate analyses of the compound for Br. could not be 

 obtained, though the results pointed to the formula CisHigOsBr. for the 

 compound. As already pointed out in the earlier part of this paper, this 

 bromide was assumed to be the anhydro salt of a tetramethoxy benzo- 

 pyranol: accordingly, it seemed feasible to try to isolate and obtain the 

 corresponding colour-base in a pure condition. The method of Watson and 

 Senn Jour. Chem. Soe., 1915, cvii, p. 1477), for the isolation of colour-bases 

 from their eoiTesponding benzopyranol anhydro-salts, was successfully tried. 



The bromide was added to 50 c.c. of 80 per cent, alcohol, and 20 c.c. of 

 concentrated ammonia (s. g. 0880) added ; 100 c.c. of a saturated solution of 

 ammonium ehloiide were then mixed with the solution, and the whole sub- 

 sequently extracted with three successive volumes (100 c.c. each) of ether. 

 The combined ether extracts were allowed to stand for an hour over 

 anhydrous potassium carbonate, and the ether afterwards distilled off on a 

 water-bath. The white crystalline residue was then recrystallized, once 

 from chloroform and twice from absolute aleohoL The compound was then 

 obtained as colourless glistening needles, which melted sharply at l-3o- 

 134" C, and was free from traces of halogens. On pouring dilute hydro- 

 chloric acid on some of the crystals, the latter at once assumed a beautiful 

 red tint, due to their transformation into the corresponding anhydrochloride. 

 This base is sparingly soluble in ether, easily soluble in chloroform, some- 



