Chloride → Methyl 3,4-dimethoxy-5-(3-oxopropyl)benzoate

Temperature

-78 °C

To a solution of oxallyl chloride (1.34 mL, 15.4 mmol) in CH2Cl2 (30 mL) at −78° C. was added a solution of dimethyl sulfoxide (DMSO) (1.45 mL, 20.5 mmol) in CH2Cl2 (10 mL) via cannula over the course of 1 min. After stirring for 20 min at −78° C. a solution of 3-(3-hydroxypropyl)-4,5-dimethoxybenzoic acid methyl ester (1.30 g, 5.12 mmol) in CH2Cl2 (10 mL) was added via syringe. The reaction was stirred at −78° C. for 45 min then treated with triethylamine (Et3N) (5.7 mL, 10 eq.). After 20 min at −78° C. the reaction was allowed to warm to room temperature. After stirring at room temperature for 30 min, the reaction mixture was diluted with 1:1 EtOAc:hexanes (250 mL), washed with H2O (2×200 mL), brine (200 mL), dried over MgSO4 and then concentrated under reduced pressure. The crude product was purified by flash column chromatography on silica gel using 50% EtOAc in hexanes as an eluent to furnish 3,4-dimethoxy-5-(3-oxopropyl)benzoic acid methyl ester (1.20 g, 93%).

1. additionwas added via syringe
2. waitAfter 20 min at −78° C. the reaction was allowed
3. temperatureto warm to room temperature
4. stirringAfter stirring at room temperature for 30 min
5. washhexanes (250 mL), washed with H2O (2×200 mL), brine (200 mL)
6. dry with materialdried over MgSO4
7. concentrationconcentrated under reduced pressure
8. customThe crude product was purified by flash column chromatography on silica gel using 50% EtOAc in hexanes as an eluent

ORD record

ord-79cd415607ad40daaddd96bc455b7a69

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07691843B2