Patent GB-880935-A (GB)
Title: Substituted dimethyl-benzoquinones and dimethyl-benzohydroquinones and a process forthe manufacture thereof
IPC: C07C50/06
Filed: 1959-12-31
Abstract: The invention comprises dimethylbenzo-(1 : 4)-quinones and -hydroquinones substituted by one or two radicals of formula <FORM:0880935/IV (b)/1> wherein n is 0-9 or the corresponding radical in which the double bond within the brackets is replaced by a single bond and also the 1-carboxylic acid acyl derivatives of the substituted hydroquinones.  They are prepared by condensing a 2 : 3-, 2 : 5- or 2 : 6-dimethyl-benzo-1 : 4-hydroquinone or a 1-acyl derivative thereof in the presence of an acidio condensing agent, with a compound of formula <FORM:0880935/IV (b)/2> wherein X is a halogen atom or a hydroxy, acyloxy or alkoxy radical containing not more than eight carbon atoms and n is 0-9, or the corresponding compounds wherein the double bonds within the brackets are replaced by single bonds, and, if desired, hydrolysing the condensation product to remove the 1-acyl radical if present and/or oxidising the product to the corresponding benzoquinone derivative.  In Examples: (1) 2 : 3-, 2 : 5- or 2 :6-dimethylbenzo-1 : 4-hydroquinone is reacted with isophytol in ether solution in the presence of zinc chloride and acetic acid, the product being separated chromatographically to give 2 : 3-, 2 : 5- or 2 : 6-dimethyl-3-mono- and -3 : 5-di-phytyl-benzo-1 : 4-quinones; (2) 2 : 3-dimethyl-benzo- 1 : 4-hydroquinone is reacted with isophytol in dioxan solution in the presence of zinc chloride to give 2 : 3-dimethyl-5-phytyl-benzo-1 : 4-hydroquinone which is oxidised with silver oxide in ether solution to the corresponding quinone; (3) 2 : 3-dimethyl-benzo-1 : 4-hydro-quinone is reacted with 3 : 7 : 11 : 15 : 19 : 23 : 27 : 31 : 35-nonamethylhexatriacontanonaen-(2 : 6 : 10 : 14: 8: 22 : 26 : 30 : 34)-ol-(1) as in (1) the product is oxidised as in (2) to the quinone which is purified chromatographically to give 2 : 3-dimethyl-5-[31 : 71 : 111 : 151 : 191 : 231 : 271 : 311 : 351-nonamethyl-hexatriacontanonaen-(21 : 61 : 101 : 141 : 181 : 221 : 261 : 301 : 341)-yl-(11)]-benzoquinone-(1 : 4); (4) as in (3) but using 3 : 7 : 11 : 15 : 19 : 23 : 27 : 31 : 35 : 39-decamethyl-tetracontadecaen-(2 : 6 : 10 : 14 : 18 : 22 : 26 : 30 : 34 : 38)-ol-(1), 2 : 3-dimethyl-5-[31 : 71 : 111 : 151 : 191 : 231 : 271 : 311 : 351 : 391-decamethyl-tetracontadecaen- (21 : 61 : 101 : 141 : 181 : 221 : 261 : 301 : 341 : 381)-yl-(11)]-benzoquinone-(1 : 4) is obtained; (5) 2 : 3-dimethyl-benzo-1 : 4-hydroquinone 1-benzoate is reacted in dioxan with isophytol in the presence of boron trifluoride etherate and the product purified chromatographically to give 2 : 3-dimethyl-4-benzyloxy-6-phytyl-phenol which is saponified with methanolic potassium hydroxide and oxidised as in (2); (6) 2 : 3-dimethyl-benzo-1 : 4-hydroquinone is reacted with nerolidyl acetate or farnesyl methyl ether in ethyl acetate in the presence of zinc chloride, the product oxidised as in (2) and purified chromatographically.  2 : 5 Dimethyl-benzo-1 : 4-hydroquinone is prepared by reduction of the corresponding quinone with hydrogen in ether solution in the presence of a palladium/lead/calcium carbonate catalyst.  3 : 7 : 11 : 15 : 19 : 23 : 27 : 31 : 35-nonamethyl-hexatriacontanonaen-(2 : 6 : 10 : 14 : 18 : 22 : 26 : 30 : 34)-ol-(1) is prepared by saponification of the residue from a petroleum ether extraction of tobacco dust with methanolic potassium hydroxide under nitrogen and chromatographic purification of the saponification product.  3 : 7 : 11 : 15 : 19 : 23 : 27 : 31 : 35 : 39-decamethyl-tetracontadecaen-(2 : 6 : 10 : 14 : 18 : 22 : 26 : 30 : 34 : 38)-ol-(1) is prepared by reacting the alcohol specified in the preceding paragraph with phosphorus tribromide to give the corresponding bromide, treating this with ethyl acetoacetate and p sodium ethoxide to give 6 : 10 : 14 : 18 : 22 : 26 : 30 : 34 : 38-nonamethyl-nonatricontanonaen-(5, 9, 13, 17, 21, 25, 29, 33, 37) -ore- (2) which is dissolved in ether and reacted with sodium acetylide in liquid ammonia to give 3 : 7 : 11 : 15 : 19 : 23 : 27 : 31 : 35 : 39-decamethyl-tetracontanonaen-(6 : 10 : 14 : 18 : 22 : 26 : 30 : 34 : 38)-yne-(1)-ol-(3) which is partially hydrogenated using a palladium/lead/calcium carbonate catalyst as specified above to 3 : 7 : 11 : 15 : 19 : 23 : 27 : 31 : 35 : 39-decamethyl-tetra-contadecan-(1 : 6 : 10 : 14 : 18 : 22 : 26 : 30 : 34 : 38)-ol-(3).  This carbinol is converted into the corresponding bromide which is boiled with acetone and sodium acetate.  The mixture filtered, the residue refluxed with alcoholic sodium hydroxide and extracted with ether.