Phenylacetic Acid → HCID 86754755, compound

Participants

Reaction Conditions

Reaction Steps

A single necked 1-L flask charged with 2,3-dichlorobenzaldehyde (87.5 g, 0.5 mol), phenylacetic acid (4.08 g, 0.030 mol), isopropanol (662 mL), methyl acetoacetate (64.0 g, 0.55 mol), and N-methylbenzylamine (3.6 g, 0.030 mol). The flask was placed on a rotary evaporator equipped with a thermowell (via steam duct) for monitoring internal temperature and the flask heated and agitated to bring flask contents up to 55-65° C. for approximately 4-5 hours. The mixture was concentrated by removing 250-350 g of distillate at about 45-65° C. (internal temperature) and the contents gradually cooled in an ice bath to about 0-5° C. The precipitated MBI solids were isolated by filtration and washed with about isopropanol (75-80 g). The washings were combined with the filtrate. The combined filtrates and washings were re-heated to 55-65° C. for one hour, and concentrated by removing about 175-225 g of the distillate at about 45-65° C. (internal temperature). The contents were again gradually cooled in an ice bath to collect a second crop of MBI solids which were isolated by filtration on the same filter funnel containing the first crop of solids. The combined first and second crop solids were washed with 4×80 g of isopropanol and dried in vacuo at ambient temperature. This gave MBI as a white solid (85.2 g, 62.4% Yield based on dichlorobenzaldehyde). LC analysis showed 99.91% MBI [97.63% A-isomer+2.28% B-isomer].

Provenance & Evidence