Pyridine → HCID 54183868, compound

Participants

Reaction Conditions

Reaction Steps

A slurry of anhydrous magnesium chloride (571 g, 6.0 moles) and methyl acetoacetate (697 g, 6.0 moles) in 3 l of acetonitrile was stirred in an ice-salt bath as 972 ml of pyridine (12 moles) was added at such a rate that the temperature did not exceed 5° C. (addition time 2 hrs.). The cooling bath was removed and toluene (500 ml) was added at once followed by the addition of a solution of 1255 g of 2,6-dichlorobenzoyl chloride (6.0 moles) in 1.5 l of toluene over one hour (final temperature 25° C.). The reaction was heated at reflux for 5 hours, and then allowed to cool over 14 hours to room temperature. The reaction was cooled in an ice bath to 0° C., and 400 ml of concentrated sulfuric acid (7.3 moles) was then added to the reaction mixture at a rate to maintain a temperature below 15° C., followed by 1.5 l of water. The mixture was stirred for 30 min. The organic layer was isolated and washed with 3 l of water. The acidic aqueous washes were back-extracted with 1 l of toluene. The product was extracted from the combined organic layers with an aqueous potassium carbonate solution (3.6 moles in 3 l water) and with a second potassiam carbonate solution (0.4 moles in 1 l water). The combined basic aqueous layers were washed with toluene (1 l) and acidified with concentrated hydrochloric acid. The resulting solid was isolated by filtration, washed with water (2×2 l), and dried under vacuum at 50° C. to give 1008 g (58%) of a granular orange solid.

Provenance & Evidence