OF ARTS AND SCIENCES. 2G7 



XIII. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



RESEARCHES ON THE SUBSTITUTED BENZYL COM- 

 POUNDS. 



By C. Loring Jackson. 



EIGHTH PAPER. 



SUBSTITUTED BENZALDEHYDES. 

 Br J. Fleming White. 



Presented April 14, 1880. 



The ortho- and parachlorbenzaldehydes are the only compounds of 

 this class containing a single halogen atom which have been described 

 heretofore. The former, made by Henry * from salicylaldehyde by 

 treating it with an excess of phosphoric pentachloride and decompos- 

 ing the orthochlorbenzalchloride, C 6 H 4 C1CHC1 2 , formed with water 

 in a sealed tube at 170°, was a heavy colorless oil boiling between 

 210° and 220° and oxidized even by the air into orthochlorbenzoic 

 acid. 



The so-called parachlorbenzaldehyde was first made by Beilstein 

 and Kuhlberg f by boiling chlorbenzylchloride, C 6 H 4 C1CH 2 C1, with 

 plumbic nitrate and water, according to the method of Lauth and 

 Grimaux ; t also by heating chlorbenzalchloride, C 6 H 4 C1CHC1.„ with 

 water in a sealed tube at 170°, and by treating benzaldehyde with 

 chlorine in presence of iodine. Later, Berlin § obtained it by dis- 

 tilling trichlorbenzylamine, (C 6 H 4 C1CH 2 ) 3 N, with bromine and water, 

 and Sintenis || by the action of chlorine on chlorbenzylethylether, 

 C 6 H 4 C1CH 2 0C 2 H 5 . They all describe it as a heavy oil, and Berlin 

 gives its boiling-point as 210°- 220°. 



* Ber. d. ch. G., 1869, p. 135. § Ann. Chem. Pha-rm., cli. 140. 



t Ann. Chem. Pharm., cxlvii. 352. I| Ber. d. ch. G., 1871, p. 697. 

 t Ibid., cxliii. 80. 



