Dicyclohexylcarbodiimide → 428452-46-4

Commercially available 2,2-difluorosuccinic acid (8.0 g, 51.9 mmol) was dissolved in THF and cooled on ice before addition of 1,3-dicyclohexylcarbodiimide (11.8 g, 57.2 mmol). The mixture was stirred at room temperature for 3 hours, cooled and filtered. The filtrate was concentrated in vacuo. The residue was stirred with methanol (50 ml) for 3 hours at room temperature and then solvents were removed in vacuo to afford the crude ester as an oil (8.4 g). The oil was purified by column chromatography on silica gel column and elution with a 0-100% ethyl acetate/toluene gradient to afford 2,2-difluorosuccinic acid 1-methyl ester as a colorless oil (6.8 g).

1. temperaturecooled
2. filtrationfiltered
3. concentrationThe filtrate was concentrated in vacuo
4. stirringThe residue was stirred with methanol (50 ml) for 3 hours at room temperature
5. customsolvents were removed in vacuo
6. customto afford the crude ester as an oil (8.4 g)
7. customThe oil was purified by column chromatography on silica gel column and elution with a 0-100% ethyl acetate/toluene gradient

ORD record

ord-cd6f12bc4f3f45308e5b34d9da9ad1b1

Source dataset

uspto-grants-2004_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06821960B2