Pyridine → HCID 58577920, compound

Participants

Reaction Steps

A solution of methyl 3-(5-(2-ethyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-7-yl)pyridin-2-yloxy)-2,2-dimethylpropanoate B-10 (248.0 mg, 0.60 mmol) and dry pyridine (97.0 μL, 1.20 mmol) in anhydrous methylene chloride (3.0 mL) was added dropwise to a solution of triphosgene (71.2 mg, 0.24 mmol) in anhydrous methylene chloride (3.0 mL) at −20° C. under an atmosphere of argon. The reaction mixture was allowed to warm to room temperature over 30 mins and was stirred for 3 h at room temperature. It was then successively diluted with methylene chloride (25 mL), quenched with a 1 N aqueous solution of hydrogen chloride (1.0 mL), diluted with water (10 mL) and decanted. The aqueous layer was extracted with methylene chloride (3×30 mL); the combined extracts were washed with a 1 N aqueous solution of hydrogen chloride (20 mL), brine (20 mL), dried over anhydrous magnesium sulfate, filtered and concentrated to dryness under reduced pressure. The light pink solid methyl 3-(5-(4-(chlorocarbonyl)-2-ethyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-7-yl)pyridin-2-yloxy)-2,2-dimethylpropanoate B-11 (265.0 mg, Yield=100%) was used for the next step without purification and stored at −20° C. under an atmosphere of nitrogen. MS (ESI) [M+1]+ 433.

Provenance & Evidence