Veratrole

Description1, 2-Dimethoxybenzene, commonly known as veratrole, is an organic compound with the formula C6H4(OCH3)2. It is a colorless liquid with a pleasant odor and slight solubility in water. It is the dimethyl ether derived from pyrocatechol, too. 1, 2-Dimethoxybenzene is naturally occurring. Its biosynthesis entails the methylation of guaiacol by guaiacol O-methyltransferase.1, 2-Dimethoxybenzene is an insect attractant. Guaiacol O-methyltransferase gene is first scent gene discovered so far in any plant species.

Uses1, 2-Dimethoxybenzene is a building block for the organic synthesis of other aromatic compounds. Veratrole is relatively electron-rich and thus readily undergoes electrophilic substitution. An example of the use of veratrole is in the synthesis of Domipizone. Veratrole can easily be brominated with NBS to give 4-bromoveratrole.

OccurrenceReported present in asparagus (raw and cooked), bonito (dried), broccoli (cooked), cauliflower (cooked), cognac, endive, grape, Gruyere de Comte cheese, guava, leek (raw and heated), olive, peas, rhubarb, rice bran and vanilla extract.

Uses1,2-Dimethoxybenzene was used to investigate the electroantennogram response of vine weevil, Otiorhynchus sulcatus to plant volatiles.

UsesVeratrole is common reagent in organic synthesis such as the synthesis of arizonins B1 and C1. Also used in the synthesis of pharmacophores of salmeterol and roflumilast as dual β2-adrenoreceptor agonists-PDE4 inhibitors.

General Description1,2-Dimethoxybenzene reacts with Li{N(SO2CF3)2} to yield molecular crystal [Li{N(SO2CF3)2}{C6H4(OCH3)2}2] having solid-state lithium ion conductivity. It is a potential pollinator attractant of the nocturnal moth Hadena bicruris.

PreparationPrepared by methylation of pyrocatechol.1,2-Dimethoxybenzene can also be prepared from Catechol. The specific synthesis steps are as follows: Aqueous sodium hydroxide(40%,175 ml)is added dropwise during 3 hr at 18-22 to a well stirred mixture of catechol (50 g,0.45 mole),sodium hydrosulphite (20 g,0.115 mole),dimethyl sulphate (110 ml,146.63 g, 1.16 mole)and alcohol (150 ml).Ice (1 kg)is added to the reaction mixture and left overnight at room temperature.It is extracted with ether (2x 200 ml).The ether extract is washed with water,dried (anhydrous sodium sulphtate)and distilled.Veratrole is obtained as oil.Yield 52.75 g (84.1%).B.p.207°(1it.3b.p.207).