72 



II . A. Drushel — Hydrolysis of Esters of 



some time, but when the hydrolysis is made in the presence of 

 an initial decinormal concentration of halogen acid the accel- 

 erating effect of the halogen substituted propionic acid and of 

 the subsequently liberated halogen acid is negligible in com- 

 parison to the accelerating effect of the added catalyzing halo- 

 gen acid. By making occasional titrations with decinormal 

 silver nitrate, the amount of halogen acid liberated in the sec- 

 ondary reaction was ascertained. The results obtained in the 

 absence of any added catalyzing acid are recorded in Tables II 

 and III. 



Table I. 



Ethel esters of halogen substituted propionic acid in N/10 hydrochloric 

 or hydrobromic acid. 







Ethel 



Ethyl 



Ethyl 



Ethyl 



Ethyl 



a-chlor- 



a-brom- 



/3-chlor- 



fl-brom- 



propionate 



propionate 



propionate 



propionate 



proprionate 



Time 





Time 







Time 







in min. 



10 5 K 



in min. 



10 5 K 

 A. 



10 6 K 

 At 25° C. 



in min. 



10 5 K 



10 5 K 



60 



70-3 



420 



28'8 



21-3 





9-6 



(8-40)* 



360 



71-8 



1330 



30-0 



21 - 2 





9-9 



8-18 



600 



70-2 



1900 



29-3 



20-6 





(10-6) 



* 8-12 



1380 



70-5 



2790 



29-3 



20-3 





9-8 



8-12 



2220 



69-2 



4215 



28-1 



21-6 





9-8 



8-16 



2800 



70-7 



4800 



27-2 



21-5 





9-7 



8-16 







5700 



27*0 



20-9 





9-7 



8-17 





70-45 



28-5 



21-06 



9-76 



9-15 









B. 



At 35° C. 









200 



177-9 



180 



57-2 



39-4 





25-0 



22-2 



260 



177-4 



360 



56-5 



38-3 





23-3 



21-4 



380 



177-4 



510 



58-3 



41-0 





24-3 



22-4 



500 



177-2 



1380 



57-4 



393 





23-8 



210 



705 



177-1 



1560 



57-2 



39-6 





23-8 



21-4 



1410 



176-8 



1800 



55-8 



38-3 





24-4 



21-3 







1980 



56-3 



37-8 





23-1 



21-5 





177-3 



56-9 



38-9 



23*9 



21-6 









C. 



At 50° C. 









20 



534 



20 



186-1 



92-5 



110 



86-5 



52-3 



35 



541 



50 



192-5 



94-8 



180 



85-2 



53-4 



50 



529 



110 



181-2 



96-0 



300 



89-0 



56-3 



80 



541 



180 



185-7 



90-0 



420 



86-0 



56-7 



110 



537 



300 



195-8 



90-3 



580 



83-8 



53-8 



180 

 300 



527 

 528 



420 



183-4 



91-5 











86-1 



54-5 





187-4 



92-5 







533-8 















* Not included in the average. 







