1,8-Naphthyridin-2(1H)-one, 4-chloro-1-methyl- synthesis

10synthesis methods

Product Name:1,8-Naphthyridin-2(1H)-one, 4-chloro-1-methyl-
CAS Number:1009360-86-4
Molecular formula:C9H7ClN2O
Molecular Weight:194.62

1,8-Naphthyridin-2(1H)-one, 4-hydroxy-1-methyl-

97510-72-0
3 suppliers
inquiry

1,8-Naphthyridin-2(1H)-one, 4-chloro-1-methyl-

1009360-86-4
3 suppliers
inquiry

Yield:1009360-86-4 24%

Reaction Conditions:

with trichlorophosphate at 100; for 2 h;

Steps:

4 preparation of 4-chloro-1-methyl-1,8-naphthyridin-2-one (compound L-5)

4-hydroxy-1-methyl-1,8-naphthyridin-2-one (compound L-4, 150.0 g, 850 mmol) in phosphorus oxychloride (300 mL) was stirred at 100 °C for 2 hours. The reaction mixture was concentrated in reduced pressure to remove the phosphorus oxychloride. The residue was neutralized by adding saturated aqueous NaHCO3 at room temperature to pH = 7 8, and the mixture was extracted with DCM (1000 mL) twice. The combined organic layer was washed with sat. brine (500 mL), dried over Na2SO4 and concentrated in vacuo to give a crude product, which was purified by silica gel chromatography (PE/EtOAc = 1:0 to 7:1) to afford compound L-5 (39 g, 24% yield). LCMS(M+H)⁺: 195, ¹H NMR (400 MHz, DMSO-d6) ppm 8.75 (dd, J = 4.6, 1.6 Hz, 1H), 8.32 (dd, J = 7.9, 1.7 Hz, 1H), 7.44 (dd, J = 8.0, 4.6 Hz, 1H), 7.03 (s, 1H), 3.66 (s, 3H).

References:

WO2020/207991,2020,A1 Location in patent:Page/Page column 55-56

59514-93-1 Synthesis