Oxalyl chloride → 2-Bromo-5-methylbenzoyl chloride

To a suspension of 2-bromo-5-methyl benzoic acid (1.0 g, 0.00465 mole) in dry dichloromethane (10 mL) was added oxalylchloride (1.22 mL, 0.013 mole) dropwise at 0° C. followed by 1-2 drops of N,N-dimethyl formamide. The reaction mixture was then stirred for 2 hours at room temperature and the solvents were evaporated and the product dried under vacuum to yield 2-bromo-5-methylbenzoyl chloride which was used for the next step. To a precooled solution of 2-bromo-5-methyl benzoyl chloride in toluene (5 mL) was slowly added a pre-cooled solution of triethylphosphite (1.05 mL, 0.00604 mole) in toluene. The reaction was then left at room temperature for overnight. The solvents were then evaporated on a rotovap. The resultant product was diluted with dichloromethane (50 mL), washed with saturated sodium bicarbonate (NaHCO3, 25 mL), and then dried over magnesium sulfate (MgSO4). Filtration and solvent evaporation provided 1.1 g of product. Flash chromatography on silica gel using 0%-5% ethyl acetate/dichloromethane followed by drying of the product under high vacuum afforded 0.900 g of (2-bromo-5-methylbenzoyl)phosphonic acid diethyl ester. B. The material from A above was used to prepare [2-bromo-5-methylbenzoyl)difluoromethyl]phosphonic acid diethyl ester following a procedure similar to Example 80C. This material was used to prepare Compound 82 following a procedure similar to Example 40. 1H NMR: (DMSO-d6, 400 MHz) δ 7.56 (d, 1H, J=8.4 Hz), 7.40 (s, 1H), 7.19 (d, 1H, J=8.0 Hz), 2.28 (s, 3H). MS (ion spray): m/z 300.15/301.05 (M−H)

1. customthe solvents were evaporated
2. customthe product dried under vacuum

ORD record

ord-8299b1d6cc874abda4115cedb1528380

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07829737B2