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21900-45-8

Benzoyl chloride, 4-bromo-2-methyl- synthesis

2synthesis methods
68837-59-2 Synthesis
4-Bromo-2-methylbenzoic acid

68837-59-2
346 suppliers
$5.00/1g

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Yield:21900-45-8 100%

Reaction Conditions:

with oxalyl dichloride;N,N-dimethyl-formamide in dichloromethane at 20; for 9 h;

Steps:



Intermediate 8: (R)-2-(4-bromo-2-methylphenyl)propan-l-ol; Intermediate 8A:; [00211] To a suspension of 4-bromo-2-methylbenzoic acid (30.5 g, 142 mmol) in DCM (250 mL), were added oxalyl chloride (14.9 mL, 170 mmol) and DMF (20 μL, 0.258 mmol). The suspension was stirred at rt for 9 h, then concentrated to afford the acid chloride (33.1 g, quantitative) as an off-white crystalline solid. To a mixture of N,O-Dimethylhydroxylamine hydrochloride (16.60 g, 170 mmol) and pyridine (34.4 mL, 425 mmol) in DCM (250 mL) and acetonitrile (50 mL) at 0 0C, was added a solution of the acid chloride prepared above in DCM (100 mL), dropwise over 20 min. The resultant suspension was removed from the ice bath and was stirred at rt for 6 h. The reaction mixture was washed with 2N HCl (2x), H2O and brine, dried (Na2SO4), filtered through 1" SiO2 and concentrated to afford Intermediate 8A (34.6 g, 134 mmol, 95 % yield) as a light brown oil. MS (ESI) m/z 258.1 (M+H)+.

References:

WO2008/79836,2008,A2 Location in patent:Page/Page column 93-94