218 



AROMATIC ALDEHYDES AND KETONES [119 B-iao C. 



aldehyde on reduction with alkaline 

 sulphide in dilute alcohol, or with sul- 

 phur in hot fuming 1 sulphuric acid. 



p-Nitrotoluene and oxalic ester com- 

 bine in the presence of sodium ethoxide 

 to form p-nitrophenylpyroracemic acid, 

 which gives p-nitrobenzoic aldehyde on 

 oxidation with chromic acid mixture 

 (Reissert, Ber. SO, 1049). p-Nitro- 

 toluene by the action of amyl nitrite in 

 presence of sodium ethoxide gives p- 

 nitrobenzaldoxime(Angeli and Angelico, 

 Atti Real. Accad. [5] 8, II, 28 ; Ch. 

 Centr. 1899, 2, 371; Meister, Lucius, 

 and Briining, Germ. Pat. 107095 of 

 1898; Ch. Centr. 1900,1, 886; Lap- 

 worth, Trans. Ch. Soc. 79, 1274). 



[F.] Paracresol [63], on oxidation 

 with sulphuric and chromic acids in 

 presence of acetic anhydride, gives p- 

 hydroxybenzaldehyde triacetate (Thiele 

 and Winter, Ann. 311, 357). The 

 triacetate is decomposed with the forma- 

 tion of the aldehyde on heating with 

 dilute acid (Ibid.}. 



120. Anisic Aldehyde; 

 Faramethoxybenzoic Aldehyde. 



CHO 



OCH, 



NATURAL SOURCES. 



Russian oil of aniseed (from Pim- 

 pinella anigiim) contains a small quantity 

 of this aldehyde (Bouchardat and Tardy, 

 Bull. Soc. [3] 15, 612). French oil of 

 bitter fennel contains anisic aldehyde 

 (Tardy, Rid. [3] 17, 580). In Chinese 

 star-anise oil (Ibid. [3] 27, 990). The 

 existence of the aldehyde in these oils 

 may be due to the oxidation of ane- 

 thole. 



SYNTHETICAL PROCESSES. 



[A.] Vrom.p-hydroxybenzaldehyde [119] 

 by methylation with potassium hydr- 

 oxide and methyl iodide [13] in methyl 



alcoholic solution (Tiemann and Herz- 

 feld, Ber. 10, .63). 



[B.] From phenol [60] through ani- 

 sole by methylation (Cahours, Ann. 78, 

 226 ; Vincent, Bull. Soc. [2] 40, 1 06 ; 

 Kolbe, Journ. pr. Ch. [2] 27, 425; 

 Auer, Ber. 17, 672 ; Krafft and Roos, 

 Germ. Pat. 76574 of 1893; Ber. 17, 

 Ref. 955 ; Ullmann and Wenner, Ber. 

 33, 2476). The latter combines with 

 hydrogen cyanide [172] in presence of 

 hydrogen chloride and aluminium chlor- 

 ide to form a compound which gives 

 anisic aldehyde on decomposition with 

 dilute acids (Gattermann, Ber. 31, 



Or from anisole and carbon mon- 

 oxile, the latter being converted into 

 carbonyl chloride, and then into chlor- 

 carbamide by the action of ammonium 

 chloride (Gattermann and Schmidt, 

 Ber. 20, 118; 858; Ann. 244, 30). 

 Chlorcarbamide and anisole combine in 

 the presence of aluminium chloride to 

 form anisamide (Gattermann, Ann. 244, 

 62), and this on reduction with sodium 

 amalgam in acid solution gives anisyl 

 alcohol (Hutchinson, Ber. 24, 175), 

 from which the aldehyde can be obtained 

 as under E. Or anisamide can be 

 hydrolysed to anisic acid and treated as 

 under P. 



Or from anisole and ethyl alcohol [14] 

 through mercury fulminate (see under 

 benzoic aldehyde [114; A]). The latter 

 condenses with anisole in presence of 

 aluminium chloride and hydrate to form 

 o- and p-anisic aldehyde and oxime and 

 p-anisic nitrile (Scholl and Hilgers, 

 Ber. 36, 648). 



Anisole also combines with ethyl- 

 oxalyl chloride = chlorethanalic ester 

 (from oxalic acid [Vol. II] and ethyl 

 alcohol [14]; Henry, Ber. 4, 599; 

 Anschiitz, Ber. 19, 2159; Peratoner 

 and Strazzeri, Gazz. 21, 301) in presence 

 of aluminium chloride to form anisole- 

 glyoxylic ester. The acid (p-methoxy- 

 phenylglyoxylic) obtained from the 

 latter by hydrolysis gives anisic alde- 

 hyde on heating per se, or (better) with 

 aniline (Bouveault, Bull. Soc. [3] 17, 



943)- 



[C.] From anethole [68] by oxidation 

 (Cahours, Ann. Chim. [3] 14, 484 ; 23, 



