Phosphorus oxychloride → 7-Benzyl-4-chloro-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine

Part B: To a mixture of 7-benzyl-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-4(3H)-one 4.83 g, 20.0 mmol) in toluene (80 mL) at 25° C. was added N,N-diisopropylethylamine (3.48 mL, 20.0 mmol), followed by phosphorous oxychloride (2.24 mL, 24.0 mmol). The reaction mixture was heated at reflux for 2.00 h. After cooling to room temperature, the mixture was diluted with water and ethyl acetate. The aqueous phase was adjusted to ˜pH 7 employing saturated aqueous sodium bicarbonate solution. The phases were separated. The organic phase was washed with water and brine, dried over anhyd. sodium sulfate, filtered, and concentrated. The residue was dissolved in 1-chlorobutane, and the resulting mixture was filtered. The filtrate was concentrated under vacuum to provide 7-benzyl-4-chloro-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine (4.75 g, 91%) as an orange-red oil; Mass Spec.: m/e: 260.10/262.05 (M+H)+ [calc'd: 260.09/262.08].

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 2.00 h
3. customThe phases were separated
4. washThe organic phase was washed with water and brine
5. customdried over anhyd
6. filtrationsodium sulfate, filtered
7. concentrationconcentrated
8. dissolutionThe residue was dissolved in 1-chlorobutane
9. filtrationthe resulting mixture was filtered
10. concentrationThe filtrate was concentrated under vacuum

ORD record

ord-eb057472ab2e4a84a30e8c11eb3dee8a

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08242124B2