1,1,1,4,4,4-Hexafluoro-2,3-butanedione → Ethyl 3-amino-5,6-bis(trifluoromethyl)pyrazine-2-carboxylate

To a solution of amino-carbamimidoyl-acetic acid ethyl ester (Int E2)(1.25 g, 8.61 mmol) in DMF (5 ml) was added 1,1,1,4,4,4-hexafluorobutane-2,3-dione (5 g, 25.8 mmol) and the mixture was stirred at RT for 25 days. The yellow suspension was partitioned between EtOAc (50 ml) and water (50 ml) and the organic portion was washed with brine (30 ml), dried (MgSO4) and concentrated in vacuo. The crude product was purified by mass directed LC-MS eluting with MeCN/Water/0.1% TFA. The clean fractions were poured into EtOAc (50 ml) and washed with saturated NaHCO3 (50 ml), dried (MgSO4) and concentrated in vacuo to afford the title compound; 19F NMR (400 MHz, DMSO-d6): Peak 1 at −62 ppm, peak 2 at −64.6 ppm

1. customThe yellow suspension was partitioned between EtOAc (50 ml) and water (50 ml)
2. washthe organic portion was washed with brine (30 ml)
3. dry with materialdried (MgSO4)
4. concentrationconcentrated in vacuo
5. customThe crude product was purified by mass
6. washeluting with MeCN/Water/0.1% TFA
7. additionThe clean fractions were poured into EtOAc (50 ml)
8. washwashed with saturated NaHCO3 (50 ml)
9. dry with materialdried (MgSO4)
10. concentrationconcentrated in vacuo

ORD record

ord-641da2f31c76452d92b852fee5621d8d

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09034879B2