Methanol → 3-(2-methyl-5-nitro-4-oxo-4H-quinazolin-3-yl)-piperidine-2,6-dione

Temperature

170 °C

Step 4: Two vials each with a suspension of 5-nitro-2-methyl-benzo[d][1,3]oxazin-4-one (0.60 g, 2.91 mmol) and 3-amino-piperidine-2,6-dione hydrogen chloride (0.48 g, 2.91 mmol) in pyridine (15 mL) were heated at 170° C. for 10 minutes in a microwave oven. The suspension was filtered and washed with pyridine (5 mL). The filtrate was concentrated in vacuo. The resulting mixture was stirred in HCl (30 mL, 1N), ethyl acetate (15 mL) and ether (15 mL) for 2 hours. The suspension was filtered and washed with water (30 mL) and ethyl acetate (30 mL) to give a dark brown solid, which was stirred with methanol (50 mL) at room temperature overnight. The suspension was filtered and washed with methanol to give 3-(2-methyl-5-nitro-4-oxo-4H-quinazolin-3-yl)-piperidine-2,6-dione as a black solid (490 mg, 27% yield). The solid was used in the next step without further purification.

1. filtrationThe suspension was filtered
2. washwashed with pyridine (5 mL)
3. concentrationThe filtrate was concentrated in vacuo
4. filtrationThe suspension was filtered
5. washwashed with water (30 mL) and ethyl acetate (30 mL)
6. customto give a dark brown solid, which
7. filtrationThe suspension was filtered
8. washwashed with methanol

ORD record

ord-17033dbc1b1742e6a20e80ba3f8e6281

Source dataset

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07635700B2