Hydrazine → HCID 42879153, compound

Temperature

80 °C

To a solution of Intermediate 4A (100 g, 420 mmol) in ethanol (250 mL) was added hydrazine (13.83 mL, 441 mmol) in ethanol (250 mL) to give a brown solution. The reaction mixture was stirred at 80° C. for 2 h. Ethanol was removed under reduced pressure and the residue was diluted with water and extracted with ethyl acetate (3×100 mL). The combined organic layer was washed with water (2×100 mL), brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The brown solid thus obtained was purified by ISCO using 20% ethyl acetate in hexane as eluent. The combined fractions were concentrated to afford Intermediate 4B (85 g, 86%) MS(ES): m/z=233 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 14.06 (bs, 1H), 7.68-7.75 (m, 2H), 7.45-7.55 (m, 1H), 7.36 (s, 1H), 7.20 (t, J=7.53 Hz, 1H), 4.34 (q, J=7.03 Hz, 2H), 1.34 (t, J=7.03 Hz, 3H).

1. customto give a brown solution
2. customEthanol was removed under reduced pressure
3. additionthe residue was diluted with water
4. extractionextracted with ethyl acetate (3×100 mL)
5. washThe combined organic layer was washed with water (2×100 mL), brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe brown solid thus obtained
10. customwas purified by ISCO
11. concentrationThe combined fractions were concentrated

ORD record

ord-e876c70dc91f4361bdb47d2f7924d5a2

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09273058B2