7-BROMO-5-METHYLBENZOFURAN synthesis

Yield: 66%

Reaction Conditions:

with PPA in chlorobenzene for 2 h;Heating / reflux;

Steps:

39 Example 39; 7-BROMO-5-METHYLBENZOFURAN.
To a 2 L round bottom flask was added PPA (3 g), anhydrous chlorobenzene (1.0 L) and the mixture was brought to reflux followed by the slow addition of 2-bromo- 1- (2, 2-dimethyoxy-ethoxy) -4-methyl benzene (22.9 g, 83.3 mmol) in chlorobenzene (200 ml) by addition funnel over a 2 h period. The reaction was then cooled and passed through a silica plug (washed with chlorobenzene) and concentrated to a mixture of product plus 4-iodo-2-methylphenol. Column chromatography (10% EtOAc/hexane) afforded 11.54 g (66%) of product as a clear oil : 1H NMR (300 MHz, DMSO-D6) : 8 2.40 (3H, s), 7.02 (1H, d, J = 2.2 Hz), 7.39 (1H, s), 7.45 (1H, s), 8. 07 (1H, d, J = 2.2 HZ). Anal. for C9H7BRO : Calc'd: C: 51.22 H: 3.34 Found: C: 52.54 H: 3.58

References:

WYETH WO2004/103941, 2004, A2 Location in patent:Page 36-37