230 



AROMATIC ALDEHYDES AND KETONES [131 C-132 B. 



ester of the latter acid by the action of 

 alcoholic potash gives p-methoxyphenyl- 

 propiolic acid (Reychler, Bull. Soc. [3] 

 17, 512), and this on heating with 

 water to 130 yields p-methoxyaceto- 

 phenone (Ibid. 514), which can be 

 demethylated as above. 



[D.] Apigenin [140] gives p-hydroxy- 

 acetophenone among the products of 

 decomposition by heating with caustic 

 alkali (Vongerichten, Ann. 318, 131 ; 

 A. G-. Perkin, Trans. Ch. Soc. 71, 810). 



[E.] From ciiinamw acid [Vol. II] 

 through the p-nitro-acid by nitration 

 (see under p-hydroxybenzoic aldehyde 

 [119; B]). The nitro-acid (ester) on 

 bromination gives p-nitrophenyldibrom- 

 propionic acid (ester), and this by the 

 action of alcoholic potash yields p-nitro- 

 phenylpropiolic acid (Miiller, Ann. 212, 

 138; Drewsen,7^V/. 154; W. H. Perkin, 

 junr., and Bellenot, Trans. Ch. Soc. 49, 

 441). The latter on heating with dilute 

 sulphuric acid gives p-nitroacetophenone 

 (Drewsen, loc. cit. 160; Engler and 

 Zielke, Ber. 22, 203), which reduces to 

 p-aminoacetophenone (Drewsen, loc. cit. 

 162). The latter yields p-hydroxyaceto- 

 phenone by the diazo-method (Klingel, 

 Ber. 18, 2691). 



[F.] From benzene [6; I, &c.] and 

 acetic acid [Vol. II] through aniline, 

 which, on heating with acetic anhydride 

 and zinc chloride, gives p-aminoaceto- 

 phenone (Klingel, Ber. 18, 2688 ; Rons- 

 set, Bull. Soc. [3] 11, 320 : see also 

 Kohler, Germ. Pat. 56971 of 1889; 

 Ber. 24, Ref. 685). From the latter 

 as above under E. 



From benzene or toluene through p- 

 nitrobenzoic aldehyde (see under p-hydr- 

 oxybenzoic aldehyde [119; E]). The 

 latter by interaction with malonic acid 

 [Vol. II] in presence of aniline or alco- 

 holic ammonia gives p-nitrocinnamic 

 acid (Knoevenagel, Baebenroth, and 

 Wollweber, Ber. 31, 2612). Subsequent 

 steps through p-nitrophenylpropiolic 

 acid, &c., as above under E. 



NOTE -.Styrene [7] and all other generators 

 of p-nitrobenzoic aldehyde referred to under 

 p-hydroxybenzoic aldehyde [119 ; C, c.] thus 

 become generators of p-hydroxyacetophenone. 



Also from benzene through aniline, 

 p-nitraniline, p-nitrobenzonitrile and 



acid, and p-nitrobenzoyl chloride. The 

 latter with sodio-acetoacetic ester [Vol. 

 II] gives p-nitrobenzoylacetoacetic 

 ester, and this, on boiling with dilute 

 sulphuric acid, yields p-nitroacetophe- 

 none (Gevekoht, Ann. 221, 335). From 

 the latter as above under E. 



p-Nitrotoluene can also be oxidised 

 to p-nitro-benzoic acid (Glenard and 

 Boudault, Ann. 48, 344 ; Beilstein and 

 Wilbrand, Ann. 126, 255 ; 128, 257 ; 

 G. Fischer, Ann. 127, 137; 13O, 128; 

 Beilstein and Geitner, Ann. 139, 335 ; 

 Kb'rner, Zeit. [2] 5, 636; Rosenstiehl, 

 Ibid. 701). From the latter p-nitro- 

 benzoyl chloride can be obtained by the 

 usual method (Gevekoht, loc. cit.]. 



132. Ketocoximarau ; Coumaranone. 



,C(OH) 



NATURAL SOURCE. 



The compound itself has not been 

 found among natural products, but the 

 complex appears to be present in genis- 

 te'in, a colouring-matter obtained from 

 dyer's broom, Genista tincforia (A. G. 

 Perkin and Newbury, Trans. Ch. Soc. 

 75, 837). 



SYNTHETICAL PROCESSES. 



[A.] From o-hydroxyacetophenone\\SQ~\ 

 by acetylation, bromination, and the 

 action of boiling water in presence of 

 chalk on the acetyl-o-hydroxy-w-aceto- 

 phenone bromide (Friedlander and 

 Neudorf er ; see under salicylic aldehyde 

 [117; D]). 



[B.] From salicylic aldehyde [117] 

 and acetic acid [Vol. II]. Chloracetic 

 acid acts on sodium salicylic aldehyde 

 with the formation of o-aldehydophen- 

 oxyacetic acid, CHO . C 6 H 4 . OCH 2 . 

 COOH (Rossing, Ber. 17, 2990). The 

 latter, on oxidation with potassium per- 

 manganate, gives salicyloxyacetic acid, 

 COOH . C 6 H 4 . OCH 2 . COOH (Ibid. 



