3.5- Dimethoxy-phenol

Another reaction affording dienones was discovered by Taub. 3,5-Dimethoxy-phenol (4) reacts with FCIO3 in pyridine at 20° to give in good yield a 1 1 mixture of dienones (5) and (6). The 2- and 4-fluoro derivatives of (4) were identified as intermediates. 

Obtained (poor yield) by reaction of o-nitrobenzoyl chloride with 3,5-dimethoxy-phenol in the presence of aluminium chloride in ethyl ether, first at 0° for 3 h, then at 20° for 3 h (5%) [1123]. 

Obtained by addition of 4-acetoxy-2-methoxy-6-methylbenzoic acid to 2-fluoro-3,5-dimethoxy-phenol in the presence of trifluoroacetic anhydride, first at 0°, then at 20-25° for 20 h (21%) [1191]. 

Tetramethoxyisoflavone (5) was the target of the cyclisation reaction of 3,4-dimethoxy-phenol (7) with formyl-(3,4-dimethoxyphenyl)acetic acid (2) in the presence of polyphosphoric acid. 

To 5.1 g omega-phthalimidoethyl-Br and 3.1 g 2,6-dimethoxy-phenol (or analog) in 500 ml ether add 2.66 g dry AIC13 portionwise and let stand twenty-four hours at room temperature. Heat two hours at 60°, filter, wash to recover starting material and dry, evaporate in vacuum to get 25% yield of (I). To an ether solution of diazomethane from 8 g H2N-CON(NO)CH3 add 4 g (I) portionwise and filter, evaporate in vacuum to get about 100% yield of (II). Heat 2 g (II) in 20 ml aqueous HCI for four hours and cool, precipitate, filter, evaporate in vacuum the filtrate to get about 30% yield mescaline. 

A 31.0 g sample of l-allyloxy-2,4-dimethoxybenzene was gently heated with a soft flame until the internal temperature reached 215 °C. An exothermic reaction took place, with the temperature rising to 270 °C. The residue left in the flask was largely 2-allyl-4,6-dimethoxy phenol, that contained perhaps 10% of 2,4-dimethoxyphenol which resulted from the pyrolytic loss of the allyl group. This mixture was methylated without further purification. 

Dimethoxy Phenol 3,4-Dimethyl 1,2-Cyclopen tandione 5-Ethyl 3-Hydroxy 4-Methyl 2(5H)-Furanone 3-Ethyl Pyridine Furfuryl Mercaptan Geranyl Isovalerate 2,3 -Heptandione (Z)-3-Hexenyl Butyrate (Z)-3-Hexenyl Formate Hexyl Butyrate Hexyl Hexanoate Isoamyl Isobutyrate Isobutyl Formate Isobutyl Hexanoate Linalool Oxide... 

An organoleptic omission test on this mixture confirmed 3-hydroxy-4, 5-dimethyl-2(5H)-furanone to be the most important FIC for a raw cane sugar aroma, and the other main components in Table 1, i.e., vanillin, maltol, 4-pentyl butanolide, 4-vinyl phenol and 2,6-dimethoxy phenol, seemed to improve the overall sugary aroma. From these results, we( ) gave the trivial name sotolon" to 2-hydroxy-4,5-dimethyl-2(5H)-furanone, which is built up from "soto" (raw sugar in Japanese) and "olon" (enol lactone) as a main FIC in raw cane sugar. 

Triehloropheflols. In fermentation cultures, the basi-diomycete Hypholoma elongatum produces trichlori-nated phenols, e.g., 2,4,6-trichloro-3-methoxyphenol (1), C7H5CIJO2, Mr 227.47, yellow crystals, mp. 62-66 C 2,4,5-trichloro-3,6-dimethoxyphenol (2), CgHTCIaOj, Mr 257.50 2,3,5-trichloro-4,6-dimethoxy-phenol (3), CgH7CI,Oj, Mr 257.50. 

FIGURE 10.12 Pyrogram of oak wood pyrolyzed at 600°C. Peaks 1 = acetic acid, 2 = furan carboxaldehyde, 3 = 2-methoxy -methyl phenol, 4 = 2,6-dimethoxy phenol, 5 = 2,6-dimethoxy-4-propenyl phenol. 

Dimethoxy phenol Hexahydrophthalic anhydride Methacrylic anhydride Propyl 2-fuorate Vanillyl alcohol C8H10O3S... 

Ethyl(or methyl)-2. 6-dimethoxy-phenol 59-64 Violet green-blue + O 0... 

Preparation by Friedel-Crafts acylation of 3,4-dimethoxy-phenol with 2,6-dichloroben-zoyl chloride [1072]. 

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