ChemicalBook CAS DataBase List 5-Bromo-1-benzofuran

5-Bromo-1-benzofuran synthesis

13synthesis methods

Product Name:5-Bromo-1-benzofuran
CAS Number:23145-07-5
Molecular formula:C8H5BrO
Molecular Weight:197.03

4-BROMOPHENOXYACETALDEHYDE DIETHYLACETAL

112598-18-2

23145-07-5

The general procedure for the synthesis of 5-bromobenzofuran from 4-bromophenoxyacetaldehyde diethyl acetal was as follows: polyphosphoric acid (10 g) was added to a solution of benzene (50 mL), the product of step A (8.4 g). The reaction mixture was heated to reflux for 4 hours. Upon completion of the reaction, the mixture was cooled to 0 °C and slowly poured into ice water (80 mL). The aqueous phase was extracted with ether and the organic phases were combined. The ether layer was washed sequentially with saturated sodium bicarbonate solution and brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give 4.9 g of crude product in 85% yield.

112598-18-2
49 suppliers
$29.00/1g

23145-07-5
271 suppliers
$15.00/1g

Yield:23145-07-5 85%

Reaction Conditions:

with PPA in benzene for 4 h;Heating / reflux;

Steps:

34.4.B Step B
To a solution of the product from Step A (8.4g) in benzene (50ML) was added POLYPHOSPHORIC acid (10G). The mixture was heated at reflux for 4 hrs. The reaction was cooled to 0°C and poured into ice water (80ML) and extracted with ether. The ether layer was washed with saturated sodium bicarbonate and brine, dried with MGS04, filtered and concentrated in vacuo to give 4.9g of crude product (85%).

References:

PHARMACOPEIA, INC. WO2004/33440, 2004, A1 Location in patent:Page 239-240

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