117 



lost liydrobromic acid, leaviug mouovalent uitrogeu, Avbicb, by its reac- 

 tivity, drew to itself tbe radical originally attached to carbon. As Stieg- 

 litz has pointed out, this explanation would account for tbe Beckniann 

 rearrangement, and for that of tbe acid azides. 



It seemed not without interest, therefore, to determine experimentally 

 the position of the amide hydrogen in tbe halogen amide molecule. Tbe 

 two possible positions of this atom, 11 CO— N H/Cl and RC— (OH)=N 01, 

 correspond to tbe two classes of alkyl derivatives, cblor alkyl acid amides, 

 R CO N R/Cl, and chlorimido acid esters, whose properties are now 

 known. But the fact that tbe salts of such a molec\ile may have a differ- 

 ent constitution from that of the free acid would make quite uncertain any 

 conclusions drawn from the results obtained from tbe usual methods of 

 introducing an alkyl radical. 



^'on Peckmann has shoAvn that substances of an acid character react 

 readily with diazomethane. forming a methyl derivJitive of the sultstance, 

 the methyl entering where the hydrogen was attached. As the reaction 

 is carried out with the free acid in absolute ethereal solution the proba- 

 bility of a rearrangement of the molecule during the process of metbyla- 

 tion is reduced to a minimum. Ransom has shown, also, in two cases, 

 that this method of methylation can be used to advantage in deciding 

 delicate questions of constitution. 



With these ideas in view, the following work was undertaken: Benz- 

 cbloramide is best made by adding a solution of chloride of lime to a cold 

 saturated solution of benzamide, which had previously been acidified 

 with acetic acid, and extracting the oil which is formed with ether. 

 On drying the ethereal solution with calcium chloride and evaporating 

 the ether in vacuo without heating, a crystalline residue results Avhich 

 after recrystallizing from benzol was found to be 98.1 per cent. pure. 

 The purity was determined by finding the percentage of active chlorine 

 in the substance, by adding potassium iodide to a dilute alcoholic solution 

 and titrating the free iodine with sodium thiosulphate. An ethereal 

 solution of diazomethane was then prepared and some of the benzcblora- 

 mide. suspended in a little ether, added to it until the yellow color of 

 the diazomethane had nearly disappeared. Nitrogen was evolved in large 

 quantities. When the action had ceased the ether was evaporated and 

 there was left an oil with a peculiar but not unpleasant ethereal odor. 

 The oil did not solidify even in a freezing mixture. Some of it was dis- 

 solved in ligroin nnd dry liydrogen chloride passed into the solution. 



