212 A GENERAL REVIEW OF 



distillation at a high temperature which was necessary to 

 purify the substance. 



In the course of an investigation of the racemisation 

 phenomena observed in Z-benzoin and its derivatives, McKenzie 

 and Wren had occasion to prepare (53) the monomethyl ethers 

 of both i- and Z-triphenylethylene glycols. The alkylation 

 of each of the parent glycols proceeded slowly, three treat- 

 ments being necessary for completion. In each case alkyla- 

 tion of the secondary hydroxyl group alone occurred ; the 

 proof that this group was alkylated, and not the tertiary 

 hydroxyl group, has already been referred to. 



PREPARATION OF IMINO-ETHERS 



By the action of silver oxide and alkyl iodides on amides 

 and substituted amides it is possible to prepare imino-ethers : 

 a number of such preparations have been carried out by 

 Lander, the sole worker in this field. Preliminary experi- 

 ments (4) showed that benzamide was converted, by treatment 

 with excess of silver oxide and ethyl iodide, into benzimino- 

 ethyl ether, which was identified by conversion into the 

 crystalline hydrochloride C 6 H 5 . C(OC 2 H 5 ) : NH . HC1. Under 

 similar conditions, acetanilide yielded N-phenylacetiminoethyl 

 ether C 6 H 5 . N : C(OC 2 H 5 ) . CH 3 or ethyl isoacetanilide, no trace 

 of the isomeric N-ethyl ether being detected in the reaction 

 product. When, however, methyl iodide was substituted for 

 ethyl iodide in the reaction, the isomeric N-phenylacetimino- 

 methyl ether C 6 H 5 . N: C(OCH 3 ) . CH 8 and N-methylacetanilide 

 C 6 H 5 . N(CH 3 ) . COCH 3 were obtained in almost equal quantities 

 (6). Analogous results were obtained by alkylation of aceto- 

 o-toluidide, which is converted by silver oxide and ethyl iodide 

 into N-o-tolylacetiminoethyl ether CH 3 . C 6 H 4 . N: C (OC 2 H 5 ) . CH 3 

 exclusively, while with silver oxide and methyl iodide it 

 yields a mixture of the corresponding iminomethyl ether 

 and N-methylaceto-o-toluidide CH 3 . C 6 H 4 . N(CH 3 ) . CO . CH 8 . 



