Hydrazine hydrate (1:1) → 4-(4-Amino-pyridin-2-ylmethyl)-2H-phthalazin-1-one

Temperature

90 °C

A suspension of 3-(4-nitro-pyridin-2-ylmethylene)-3H-isobenzofuran-1-one (0.67 g, 2.5 mmol) in hydrazine monohydrate (0.25 g, 5.0 mmol) was heated to 90° C. for 1 hour and then cooled to room temperature. Ethanol (5 mL) added, followed by ammonium chloride (0.16 g, 3.0 mmol) and iron powder (0.28 g, 5.0 mmol), the mixture was then heated to 90° C. for 3 hours. The reaction mixture was filtered hot through celite which was washed with ethyl acetate (20 mL). The filtered was concentrated in vacuo and then diluted with ethyl acetate (10 mL) washed with brine (10 mL), dried over magnesium, sulphate and dried in vacuo to afford the title cpd as a pale yellow powder. Single peak in LC-MS analysis, (0.20 g, 31% yield) requiring no further purification, m/z (LC-MS, ESP), RT=1.58 (M+H) 253;

1. temperaturecooled to room temperature
2. temperaturethe mixture was then heated to 90° C. for 3 hours
3. filtrationThe reaction mixture was filtered hot through celite which
4. washwas washed with ethyl acetate (20 mL)
5. concentrationThe filtered was concentrated in vacuo
6. additiondiluted with ethyl acetate (10 mL)
7. washwashed with brine (10 mL)
8. dry with materialdried over magnesium, sulphate
9. customdried in vacuo
10. customto afford the title cpd as a pale yellow powder
11. customno further purification, m/z (LC-MS, ESP), RT=1.58 (M+H) 253

ORD record

ord-f5fc8a10342649b9bdecf4db908d0f34

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07902193B2