117 J-119 A.] 



SALICYLIC ALDEHYDE 



215 



25, 986), and o-nitrobenzonitrile (Sand- 

 meyer, Ber. 18, 1492). The latter can 

 be hydrolysed to o-nitrobenzoic acid, 

 and then treated as before. 



Or from benzene through aceto- 

 phenone by direct synthesis, or via 

 ethylbenzene or isopropylbenzene or 

 acetaldehydephenylhydrazone (see under 

 benzoic aldehyde [114; A]) and aceto- 

 phenone, and then as above under D. 



Acetanilide (from aniline and acetic 

 acid) on heating- with acetic and phos- 

 phoric acids and subsequent hydrolysis 

 of the acetyl-derivatives gives a mixture 

 of o- and p-aminoacetophenone (Kohler, 

 Germ. Pat. 56971 of 1889; Ber. 24, 

 Ref. 685). From the o-aminoketone as 

 under D above. 



[K.] 'From sf.yrene [7] through aceto- 

 phenone (see under benzoic aldehyde 

 [114 ; B]), and then as above under D. 



[L.] From cymene \Q\ through cumic 

 aldehyde [116] and acid and acetophenone 

 (see under benzoic aldehyde [114; K]), 

 and then as above under D. 



118. Metahydroxybenzoic Aldehyde; 



Metahydroxypheiial ; 



3-Fhenolmeth.ylal. 



CHO 



NATURAL SOURCE. 



The glucoside, salinigrin, occurs in 

 the bark of Salix discolor ( Jowett, Trans. 

 Ch. Soc. 77, 707 ; Jowett and Potter, 

 Pharm. Journ. [4] 15, 157). 



SYNTHETICAL PROCESSES. 



[A.] From benzoic aldehyde [114] 

 through the m-nitro-aldehyde by nitra- 

 tion, the m-amino-aldehyde by reduc- 

 tion, and decomposition of the diazo- 

 stannichloride by boiling with water 

 (Tiemann and Ludwig, Ber. 15, 2045 : 

 see also under vanillin [121; C]). 



[B.] From Iwizoic acid [Vol. II] 

 through the m-lwdroxy-acid (see under 



phenol [60 ; E]). The latter gives the 

 m-hydroxy-aldehyde on reduction with 

 sodium amalgam in presence of dilute 

 acid (Sandmann, Ber. 14, 969). 



NOTE : Other generators of m-hydroxyben- 

 zoic acid are m-cresol [62], cinnamic acid [Vol. II], 

 and naphthalene [12]. For references see under 

 phenol [60 ; F ; I ; J]. 



119. Farahydroxybeiizoic Aldehyde ; 



Parahydroxyplieiial ; 



4-Fkenolmethylal. 



CHO 



HO 



NATURAL SOURCES. 



Occurs in yellow Botany Bay or 

 acaroid resin from Xanthorrhcea haslilis 

 (L. Bamberger, Monats. 14, 339) ; also 

 in red Xanthorrhcea resin (Tschireh and 

 Hildebrand, Arch. Pharm. 234, 698 ; 

 Ch. Centr. 1897, 1, 422). 



The complex (p-hydroxymandeloni- 

 trile) is contained in a cyanogenetic 

 glucoside (dhurrin) occurring in the 

 young plants of Sorghum mdgare, the 

 great millet (Dunstan and Henry, Proc. 

 Roy. Soc. 70, 153). 



SYNTHETICAL PROCESSES. 



[A.] Yrompfanol [60] (with salicylic 

 aldehyde) by the action of chloroform 

 [l ; D] in presence of sodium hydroxide 

 solution (Tiemann and Reimer, Ber. 9, 

 824; Tiemann and Herzfeld, Ber. 1O, 



63)- 



Or from phenol and hydrogen cyanide 



[172] by combining the two compounds 

 in benzene solution in presence of alu- 

 minium chloride and hydrogen chloride, 

 and decomposing the product with 

 dilute acid (Gattermann and Berchel- 

 mann, Ber. 31, 1766; also Eng. Pat. 

 13453 of 1898, Bayer & Co.). Zinc 

 chloride may be used as a condensing 

 agent instead of aluminium chloride 

 (Gattermann and Kobner, Ber. 32, 278). 

 Or from phenol, ethyl alcohol [14], 





