8-Chloro-2,3-dihydro-[1,4]dioxino[2,3-b]pyridine synthesis

6synthesis methods

Product Name:8-Chloro-2,3-dihydro-[1,4]dioxino[2,3-b]pyridine
CAS Number:156840-59-4
Molecular formula:C7H6ClNO2
Molecular Weight:171.58

1,4-Dioxino[2,3-b]pyridine, 2,3-dihydro-, 5-oxide

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8-Chloro-2,3-dihydro-[1,4]dioxino[2,3-b]pyridine

156840-59-4
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$45.00/10mg

Yield:156840-59-4 1.9 g

Reaction Conditions:

with trichlorophosphate at 0 - 100; for 7 h;Inert atmosphere;

Steps:

103.3 Step-3: 8-Chloro-2,3-dihydro-[l,4] dioxino [2,3-b]pyridine

Phosphorusoxychloride (45 mL, 8 vol.) was added to 2,3-dihydro-[l,4] dioxino[2,3-b]pyridine-5-oxide (3.5 g, 0.02 mole) under N₂ at 0 °C, and then heated to 100 °C for 7 hours. Reaction mixture was concentrated under vacuum to obtain the residual compound, which was neutralized with saturated sodium bicarbonate solution pH ~ 8 and extracted with dichloromethane (100 mL x 3). The filtrate was concentrated under vacuum to obtain the crude compound which was further purified by flash chromatography using ethyl acetate: n-hexane (25:75) to obtain the title compound. Yield: 1.9 g; ^lH - NMR (DMSO- , 400 MHz) δ ppm: 4.35 - 4.36 (d, J 4.44 . 4.45 (d, J = 1.4, 4.0 Hz, 2H), 7.12 - 7.14 (d, J = 5.2 Ηζ,ΙΗ), 7.69 Ηζ,ΙΗ), Mass (m/z): 171.9 (M+H)⁺.

References:

WO2018/42362,2018,A1 Location in patent:Page/Page column 112

6636-78-8 Synthesis