Drumm — The Constitution of Catr.chin : Fart I. 47 



On analysis : — 



(a) 0'1352 grams of the substance gave 0-0774 giams of H;0 and 0'335-i 



grams of CO2, corresponding to H 64:, C 67'6 for the compound. 



(b) 0*1484 grams of the substance gave 0-0874 grams of H2O and 3672 



grams of CO,, corresponding to H 6'5, C 67'3. 

 CjjHjgOg requires 67'4 and H 6-99. 



In an estimation of the molecular weight of the compound by the elevation 

 of the boiling-point, rising a Landsberger apparatus : — 



OoOl grams of the compound gave (using absolute alcohol as solvent) an 

 elevation of O'ob" C. when the volume of the solution was 7 c.c, and 

 an elevation of 0"20" C. when the volume was 11"5 c c. The corre- 

 sponding values for the molecular weight are 319, 340 respectively. 

 CjjHjgOg requires 375. 



Ethyl catechiu tetramethyl ether is insoluble in caustic potash solution, nor 

 does its solution in alcohol afford any colour reaction with ferric chloride. It 

 dissolves in concentrated sulphuric acid, forming a yellow solution. Phosphorus 

 pentachloride has no action at ordinary temperature on the solution of this 

 compound in carbon disulphide. Ethyl catechin tetramethyl ether is sparingly 

 soluble in ether, easily in chloroform, sparingly in absolute alcohol in the 

 cold, but easily in boiling alcohol. 



Preparation of butyl catechin tetrametliyl ctlier. 

 This compound was prepared by boiling a solution of the chloride in 

 normal butyl alcohol for about ten minutes, as in the case of the correspond- 

 ing ethyl compound, which latter compound it closely resembles in its 

 properties. It crystallized from alcohol in stout prisms which melted 

 sharply at 79-80° C. 

 On analysis : — 



O'llSO grams of the substance gave 0'2984 grams of CO2 and 0-0780 

 grams of HjO, corresponding to C 68'88, H 7'31 for the compound. 

 CijHjdOg requires C 68'62, H 7'ol. 



Preparation of deliyclro catechin tetramethyl ether. 

 Five grams of the chloride of catechin tetramethyl ether were heated for 

 about half an hour with 20 c.c. of pure, dry pyridine in a 100 c.c. round i3ask 

 fitted with a reflux condenser. It was found convenient to lieafc the flask in 

 a glycerine bath maintained at a temperature of 130° C, so that the pyridine 

 boiled gently. The contents of the flask were then thrown into 300 c.c. of 

 water and allowed to stand for a few hours. At the end of this time the 

 separated, white, crystalline precipitate was filtered off on the pump, washed 

 with 50 c.c. of normal sulphuric acid, and then with 50 c.c. of water. After 



