ChemicalBook CAS DataBase List 5-Bromo-2-methoxyphenol

5-Bromo-2-methoxyphenol synthesis

12synthesis methods

Product Name:5-Bromo-2-methoxyphenol
CAS Number:37942-01-1
Molecular formula:C7H7BrO2
Molecular Weight:203.03

The 5-bromo-2-methoxyphenol is synthesized by virtue of three steps of reactions as follows: by taking o-methoxyphenol as the raw materials, performing acetylation protection on the phenolic hydroxyl by use of acetic anhydride, and then performing bromination by use of bromine under the catalysis of iron powder, and finally performing deacetylation.

90-05-1 Synthesis

90-05-1
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37942-01-1
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Yield: 90%

Reaction Conditions:

with sodium hydroxide;N-Bromosuccinimide;potassium tert-butylate;trifluoroacetic anhydride in dichloromethane;acetonitrile

Steps:

1 Preparation of 5-Bromo-2-methoxyphenol
Example 1 Preparation of 5-Bromo-2-methoxyphenol To a solution of guaiacol (5.0 g, 0.04 mol) in acetonitrile (50 ml) at ambient temperature, was added trifluoroacetic anhydride (6.2 ml, 1.1 eq.). The solution was stirred for 5 min., then 1 M potassium tert-butoxide (4.0 ml, 0.1 eq.) was added slowly. The resultant mixture was stirred for 45 min. A solution of N-bromosuccinimide (7.83 g, 1.1 eq.) in acetonitrile (50 ml) was added via addition funnel slowly. The orange solution was stirred for 24 hours then the solvent was removed in rotary evaporator to give a residue which was suspended in dichloromethane (50 ml). A 6 N aqueous solution of sodium hydroxide (20 ml) was added and the organic layer was separated and discarded. The aqueous basic layer was acidified with concentrated hydrochloric acid until pH 2 was reached. Dichloromethane (50 ml) was added to extract the acidic aqueous layer. After being separated, the organic layer was washed with brine and concentrated on rotary evaporator to afford the desired product (8 g) as a redish oil in 90% yield. Data: ¹H-NMR (CDCl₃) δ ppm: 7.1 (s, 1H, aromatic); 6.95 (d, 1H, aromatic); 6.7 (d, 1H, aromatic); 5.15 (s, 1H, OH); 3.9 (s, 3H, OCH₃).

References:

SmithKline Beecham Corporation US6624323, 2003, B1