2-Propenoic acid, 3-[3-[(phenylaMino)sulfonyl]phenyl]-, ethyl ester, (2E)- synthesis

Yield:1137621-29-4 69%

Reaction Conditions:

with triethylamine;tris-(o-tolyl)phosphine;palladium diacetate at 45 - 90;

Steps:

2

Synthesis 2 (E)-3-(3-Phenylsulfamoyl-phenyl)-acrylic acid ethyl ester (5)To the batch containing 3-bromo-N-phenyl-benzenesulfonamide (3) (the treated organic layer obtained in the previous synthesis) was added triethylamine (2.97 kg; 101.19 g/mol; 29.4 mol), tri(o-tolyl)phosphine (119 g; 304.37 g/mol; 0.4 mol), and palladium (II) acetate (44 g; 224.51 g/mol; 0.2 mol), and the resulting mixture was degassed four times with a vacuum/nitrogen purge at 45-55 C. Catalytic palladium (0) was formed in situ. The batch was then heated to 80-900C and ethyl acrylate (4) (2.16 kg; 100.12 g/mol; 21.6 mol) was slowly added over 2.75 hours. The batch was sampled after a further 2 hours and was deemed to be complete with no compound (3) being detected by HPLC. The batch was cooled to 45-55 C and for convenience was left at this temperature overnight.The batch was then reduced in volume under vacuum to 20-25 L, at a batch temperature of 45-55 C, and ethyl acetate (20 L) was added. The batch was filtered and the residue washed with ethyl acetate (3.5 L). The residue was discarded and the filtrates were sent to a 100 gallon (-454 L) reactor, which had been pre-heated to 60 C. The 30 gallon (-136 L) reactor was then cleaned to remove any residual Pd, while the batch in the 100 gallon (-454 L) reactor was washed with 2 M aqueous hydrochloric acid and water at 45-55 C. Once the washes were complete and the 30 gallon (-136 L) reactor was clean, the batch was transferred from the 100 gallon (-454 L) reactor back to the 30 gallon (-136 L) reactor and the solvent was swapped under vacuum from ethyl acetate/toluene to toluene while maintaining a batch temperature of 45-55 C (the volume was reduced to 20-25 L). At this point, the batch had precipitated and heptanes (10 L) were added to re-dissolve it. The batch was then cooled to 0-100C and held at this temperature over the weekend in order to precipitate the product. The batch was filtered and the residue was washed with heptanes (5 L). A sample of the wet-cake was taken for Pd analysis. The Pd content of the crude product (5) was determined to be 12.9 ppm.The wet-cake was then charged back into the 30 gallon (-136 L) reactor along with ethyl acetate (50 L) and heated to 40-500C in order to obtain a solution. A sparkler filter loaded with 12 impregnated Darco G60 carbon pads was then connected to the reactor and the solution was pumped around in a loop through the sparkler filter. After 1 hour, a sample was taken and evaporated to dryness and analysed for Pd content. The amount of Pd was found to be 1.4 ppm. A second sample was taken after 2 hours and evaporated to dryness and analysed for Pd content. The amount of Pd had been reduced to 0.6 ppm. The batch was blown back into the reactor and held at 40-50 C overnight before the solvent was swapped under vacuum from ethyl acetate to toluene while maintaining a batch temperature of 45-55 C (the volume was reduced to 20-25 L). At this point, the batch had precipitated and heptanes (10 L) were added to re-dissolve it and the batch was cooled to 0-10 C and held at this temperature overnight in order to precipitate the product. The batch was filtered and the residue was washed with heptanes (5 L). The filtrate was discarded and the residue was dried at 45-55 C under vacuum for 25 hours. A first lot of the title compound (5) was obtained as an off-white solid (4.48 kg, 69% overall yield from 3-bromobenzenesulfonyl chloride (1)) with a Pd content of 0.4 ppm and a purity of 99.22% (AUC) by HPLC.

References:

WO2009/40517,2009,A2 Location in patent:Page/Page column 52-53