Pyrido[2,3-f]quinoxaline synthesis

5synthesis methods

Product Name:Pyrido[2,3-f]quinoxaline
CAS Number:231-21-0
Molecular formula:C11H7N3
Molecular Weight:181.19

3673-06-1 Synthesis

3673-06-1
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7,8-Quinolinediamine, hydrochloride (1:1)

1609035-46-2
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231-21-0
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Yield:231-21-0 81%

Reaction Conditions:

in methanol at 20; for 1.5 h;

Steps:

Pyrido[2,3-f]quinoxaline (8)

Pyrido[2,3-f]quinoxaline (8). Diimine 7 (113 mg, 0.51 mmol) was added to a stirred solution of hydrochloride 5 (100 mg,0.51 mmol) in MeOH (8 mL) and stirring was continued at room temperature for 1.5 h. The volatiles were evaporated under reduced pressure and the residue was purified by FLC (silica gel, CHCl₃/MeOH 100:1, R_f = 0.25) to afford pyridoquinoxaline 8 (75 mg, 81%) as an off-white solid; mp 147-149 °C (Ref. [16] mp 146.5-147.5 °C). ¹H NMR (300MHz, CDCl₃) δ 7.69 (dd, 1H, J = 8.1, 4.3 Hz, H-8), 8.03 (d, 1H,J = 9.1 Hz, H-5), 8.08 (d, 1H, J = 9.1 Hz, H-6), 8.30 (dd, 1H, J= 8.1, 1.6 Hz, H-7), 9.01 (d, 1H, J = 1.9 Hz, H-3), 9.10 (d, 1H, J= 1.9 Hz, H-2), 9.21 (dd, 1H, J = 4.3, 1.6 Hz, H-9); ¹³C NMR(75 MHz, CDCl₃) δ 123.6, 128.1, 128.4, 130.1, 136.1, 141.3,144.4, 144.5, 145.5, 145.7, 150.7; anal. calcd for C₁₁H₇N₃: C,72.92; H, 3.89; N, 23.19; found: C, 72.97; H, 3.90; N, 23.17.

References:

Bella, Maros;Milata, Viktor [Beilstein Journal of Organic Chemistry,2013,vol. 9,p. 2669 - 2674]