P-Toluic Acid → 2,5-Pyrrolidinedione, 1-[(4-methylbenzoyl)oxy]-

2.42 g (0.021 mol) of N-hydroxysuccinimide and 5.06 g (0.050 mol) of triethylamine were initially introduced into 5 ml of ethyl acetate and the suspension was stirred at room temperature. 2.72 g (0.020 mol) of solid 4-toluic acid were added to this suspension in the course of 5 min. and then a solution of 5.64 g (0.21 mol) of diphenyl chlorophosphate was added dropwise in the course of 20 min., the reaction mixture warming to about 35° C. The mixture was stirred at room temperature for 1 hour until the reaction was complete. The reaction mixture was then diluted with 100 ml of ethyl acetate and the organic phase was washed with 50 ml each of water, 2N hydrochloric acid and 10% strength aqueous sodium hydrogencarbonate solution and then evaporated. 4.65 g of crude product were isolated, which was then stirred at room temperature for 30 minutes with 20 ml of methyl tert-butyl ether. The white crystalline solid was filtered off and dried at 50° C. and 10 mbar. 4.28 g (94%) of 4-toluic acid succinimidyl ester were isolated.

1. temperaturethe reaction mixture warming to about 35° C
2. stirringThe mixture was stirred at room temperature for 1 hour until the reaction
3. washthe organic phase was washed with 50 ml each of water, 2N hydrochloric acid and 10% strength aqueous sodium hydrogencarbonate solution
4. customevaporated
5. custom4.65 g of crude product were isolated
6. filtrationThe white crystalline solid was filtered off
7. customdried at 50° C.

ORD-Eintrag

ord-fa9e36ab9df044eca0ae8f17c3acb777

Quelldatensatz

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05734064