162 



AROMATIC ALCOHOLS AND PHENOLS 



A-G. 



SYNTHETICAL PROCESSES. 



[A.] From acetylene [l ; A], acetylene 

 dibromide by bromination (Sabanejeff, 

 Ann. 178, 116), bromacetylene by the 

 action of alcoholic soda on the dibromide 

 (Rid. Journ. Russ. Soc. 17, 175). Brom- 

 acetylene undergoes (partial) photo- 

 chemical polymerisation to 1:3: 5-tri- 

 brombenzene (Ibid. 176), and this on 

 treatment with sodium methylate in 

 methyl alcohol gives 3 : 5-dibromphenol 

 methyl ether, which on treatment with 

 sulphuric acid yields 3 : 5-dibromphenol 

 (Blau, Monats. 7, 630). The latter 

 gives phloroglucinol on fusion with 

 potash (Ibid. 632). 



Bromacetylene can also be obtained 

 from ethylene through various bromine 

 derivatives (Sawitsch, Ann. 119, 183; 

 Reboul, Ann. 124, 367 ; 125, 81), so 

 that generators of ethylene [l; A; D, &c.] 

 become generators of phloroglucinol. 



[B.] From phenol [60], being among 

 the products of fusion with caustic 

 soda (Barth and Schreder, Ber. 12, 417). 



Or from phenol through picric acid 

 (2:4: 6-trinitrophenol) by nitration of 

 the phenol or (better) its sulphonic 

 acids (Laurent, Ann. 43, 219; Schmitt 

 and Glutz, Ber. 2, 52 ; Vidal, Fr. Pat. 

 315696 of 1901 ; Journ. Soc. Ch. Ind. 

 21, 544), 2:4: 6-chlortrinitrobenzene 

 (picryl chloride) by the action of phos- 

 phorus pentachloride (Pisani, Ann. 92, 

 326 ; Clemm, Journ. pr. Ch. [2] 1, 145); 

 and 1:3: 5-triaminobeuzene by reduc- 

 tion of picryl chloride by tin and hydro- 

 chloric acid. By the action of boiling 

 water on the hydrochloride of the 

 triamine in an atmosphere of hydrogen 

 phloroglucinol is produced (Flesch, 

 Monats. 18, 755; also Eng. Pat. 445 

 of 1898 : see further Weidel and Pollak, 

 Monats. 21, 20). 



NOTE : The following synthesiscd products 

 give picric acid by the action of nitric acid and 

 thus become generators of phloroglucinol : 

 salicylic aldehyde [117] ; saligenin [55] ; sali- 

 cylic acid, coumarin, and indigo [Vol. II]. 



[C.] From resorcinol [70] by fusion 

 with caustic soda (Barth and Schreder, 

 Ber. 12, 503 ; Tiemann and Will, Ber. 

 14, 954; 18, 1323). 



[D.] From orcinol [75] by fusion with 

 caustic soda (Barth and Schreder, 

 Monats. 3, 649). 



[E.] From malonic acid [Vol. II] and 

 alcohol [14] ; the diethyl ester of the 

 acid on heating with sodium gives 

 phloroglucinoltricarboxylic ethyl ester 

 (Baeyer, Ber. 18, 3457 ; Bally, Ber. 

 21, 1767), and this by fusion with 

 potash yields phloroglucinol (Baeyer, 

 loc. cit. 3458 : see also Willstatter, Ber. 

 32, 1272). 



NOTE : According to Moore (Trans. Ch. Soc. 

 85, 165) the ester formed as the first product 

 of condensation of ethyl malonate is ethyl 

 phloroglucinoldicarboxylate. 



The tricarboxylic ester can also be 

 obtained by the action of zinc methyl 

 or ethyl on malonic ester (Lang, Ber. 

 19, 2038). 



Or from malonic ester through 

 acetonetricarboxylic ester by the action 

 of sodium and the distillation of the 

 monosodium compound of the latter 

 under reduced pressure, which gives 

 acetonedicarboxylic ester (Willstatter, 

 Ber. 32, 1274). The latter can be con- 

 verted into phloroglucinol as under P 

 below. Acetonetricarboxylic ester is 

 directly convertible into phloroglucinol- 

 tricarboxylic ester by the action of 

 malonic ester and dry sodium ethylate 

 in ethereal solution (Ibid. 1285). 



[P.] From citric acid [Vol. II] and 

 ethyl alcohol [14] through acetonedi- 

 carboxylic diethyl ester (see under 

 orcinol [75 ; C]). The latter, on treat- 

 ment with sodium in benzene solution, 

 gives a ' lactone/ which on boiling with 

 baryta water splits up into ethyl alcohol, 

 malonic acid, and phloroglucinol ( Jerdan, 

 Trans. Ch. Soc. 71, 1106). The lactone 

 is also produced by the action of sodium 

 ethylate on acetonedicarboxylic ester in 

 alcoholic solution (Ibid. Proc. Ch. Soc. 

 15, 151). 



Acetonedicarboxylic ester and malonic 

 ester condense under the influence of 

 sodium ethylate with the formation of 

 phloroglucinoldicarboxylic ester (Rimi- 

 ni, Gazz. 26, 374). 



[&.] From acetoacetic ester [Vol. II] 

 through acetonedicarboxylic ester (see 

 under orcinol . [75 ; D]), and then as 

 above under P. 



