1,2-Dimethoxybenzene Property

Melting point:

15 °C(lit.)

Boiling point:

206-207 °C(lit.)

Density 

1.084 g/mL at 25 °C(lit.)

vapor pressure 

0.63 hPa (25 °C)

FEMA 

3799 | 1,2-DIMETHOXYBENZENE

refractive index 

n20/D 1.533(lit.)

Flash point:

189 °F

storage temp. 

Store below +30°C.

solubility 

6.69g/l insoluble

form 

Powder

color 

White to cream

Odor

at 1.00 % in dipropylene glycol. sweet creamy vanilla phenolic musty

Odor Type

vanilla

Water Solubility 

Soluble in alcohol, diethyl ether, acetone, and methanol. Slightly soluble in water.

FreezingPoint 

21.0 to 23.0 ℃

Merck 

14,9956

JECFA Number

1248

BRN 

1364621

Dielectric constant

4.0899999999999999

InChIKey

ABDKAPXRBAPSQN-UHFFFAOYSA-N

LogP

1.75-2.22 at 25℃

CAS DataBase Reference

91-16-7(CAS DataBase Reference)

NIST Chemistry Reference

Benzene, 1,2-dimethoxy-(91-16-7)

EPA Substance Registry System

Veratrole (91-16-7)

Safety

Hazard Codes 

Xn

Risk Statements 

22-20/21/22

Safety Statements 

36-23-24/25

WGK Germany 

1

RTECS 

CZ6475000

TSCA 

Yes

HS Code 

29093090

Toxicity

LD50 in rats, mice (mg/kg): 1360, 2020 orally (Jenner)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

1,2-Dimethoxybenzene Chemical Properties,Usage,Production

Description

1, 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.

Uses

1, 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.

References

1.https://en.wikipedia.org/wiki/1,2-Dimethoxybenzene
2.https://pubchem.ncbi.nlm.nih.gov/compound/1_2-Dimethoxybenzene#section=Chemical-and-Physical-Properties

Chemical Properties

Colorless crystals or liquid. Soluble in alcohol and ether; slightly soluble in water.

Occurrence

Reported 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.

Uses

1,2-Dimethoxybenzene was used to investigate the electroantennogram response of vine weevil, Otiorhynchus sulcatus to plant volatiles.

Uses

Veratrole 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.

Definition

ChEBI: A dimethoxybenzene with the methoxy groups at ortho-positions.

Preparation

Prepared 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).

Taste threshold values

Intolerable at 40 ppm.

General Description

1,2-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.

Toxicology

Data from 1,2-dimethoxybenzene and read-across analog 1,4-dimethoxybenzene (CAS # 150-78-7) show that 1,2-dimethoxybenzene is not expected to be genotoxic. Data show that there are no safety concerns for 1,2-dimethoxybenzene for skin sensitization under the current declared levels of use. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the TTC for a Cramer Class I material, and the exposure to 1,2-dimethoxybenzene is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoints were evaluated based on UV spectra; 1,2-dimethoxybenzene is not expected to be phototoxic/photoallergenic. For the environmental endpoints, 1,2-dimethoxybenzene is not a PBT as per the IFRA Environmental Standards, and its risk quotients (i.e., PEC/PNEC) for the aquatic environment, based on its current volume of use in Europe and North America, are < 1

Purification Methods

Steam distil veratrole, then fractionally distil it from BaO, CaH2 or Na. Crystallise it from *benzene or low-boiling pet ether at 0o. Fractionally crystallise it from its melt. Store it over anhydrous Na2SO4. [Beilstein 6 IV 5564.]