1,4-ДИМЕТОКСИБЕНЗОЛ

Химические свойства

white crystals or powder

Вхождение

Reported found in hyacinth (Hyacinthus orientalis L.) essential oil, Rhodophyllus icterius, papaya, peppermint oil, green tea, cherimoya and cooked shrimp

Использование

1,4-Dimethoxybenzene is used as Pharmaceutical Intermediate. It is used in some paints and as a diazo dye. It is also used in perfumes and flavors in order to its floral odor. In addition, it is used on greasy skin, and with sulfur to treat acne, or as a dandruff treatment.

Подготовка

By methylation of hydroquinone using dimethyl sulfate and alkali.

Общее описание

Colorless crystals.

Реакции воздуха и воды

Slightly water soluble .

Профиль реактивности

1,4-Dimethoxybenzene is an ether. Ethers may react violently with strong oxidizing agents. In other reactions, which typically involve the breaking of the carbon-oxygen bond, ethers are relatively inert.

Синтез

An aqueous solution of sodium hydroxide (40%,175 ml) is added dropwiseduring 3 hr at 18-22° to a well stirred mixture of hydroquinone (50 g,0.45mole)，sodium hydrosulphite (2.0 g,0.115 mole), dimethyl sulphate (110ml,146.63 g,1.16 mole) and alcohol (150 ml). Ice (1 kg) is added and the reaction mixture left overnight at room temperature. It is extracted withether (2 × 200 ml). The ether extract is washed with water,dried(anhydrous sodium sulphate) and distilled.1,4-Dimethoxy benzene isobtained as an oil. Yield 52.75 g (84.1%).It solidifies on cooling and iscrystallised from ether-petroleum ether as shining needles. M.p. 55-56°.

Методы очистки

Steam distil 1,4-dimethoxybenzene, then crystallise it from hexane or *benzene, and from MeOH or EtOH, but these are wasteful due to high solubilities. Dry it under vacuum. It also sublimes under vacuum. [Beilstein 6 IV 5718.]