Yield:37993-76-3 91% ，24719-09-3 52%

Reaction Conditions:

with iodine in dimethyl sulfoxide at 100;Catalytic behavior;Temperature;Solvent;

Steps:

1 General procedure for the syntheses of 2-arylisoquinoline derivatives 4

General procedure: General procedure for the syntheses of 2-arylisoquinoline derivatives 4 3-Aminopyrazine-2-carbohydrazide (1, 77mg, 0.5mmol) 2-(arylethynyl) benzaldehydes 2 (0.5mmol), iodine (13mg, 0.05mmol), and DMSO (5.0mL) was added into a dry 25mL flask. The reaction mixture was stirred at 100°C for 4-10h until all the 1 and intermediate product hydrazone were consumed which was monitored by TLC.
The separation and purification of the products 4 were the same to those of 3. In the process of 4a, the filtrate was extracted with ethyl acetate (30mL*3). The organic layer was combined and dried by anhydrous Na₂SO₄. The ethyl acetate was recovered by rotary evaporation, and the residue was purified by column chromatography using ethyl acetate and petroleum ether (2:1) as an eluant to give 3-amino-N-hydroxypyrazine-2-carboxamide (8) in 52% yield. 4.2.1 3-Phenylisoquinoline (4a) M.p. 104-105°C (Lit.²⁰ 103-104°C); ¹H NMR (CDCl₃, 400MHz): δ_H 7.39-7.44 (m, 1H, ArH), 7.49-7.59 (m, 3H, ArH), 7.66-7.70 (m, 1H, ArH), 7.86 (d, J=8.0Hz, 1H, ArH), 7.98 (d, J=8.4Hz, 1H, ArH), 8.06 (s, 1H, ArH), 8.11-8.14 (m, 2H, ArH), 9.33 (s, 1H, ArH). ¹³C NMR (CDCl₃, 100MHz): δ_C 116.5, 126.9, 127.0, 127.1, 127.6, 127.8, 128.5, 128.8, 130.5, 136.7, 139.6, 151.3, 152.4. IR (KBr): ν 2912, 1625, 1585, 1562, 1515, 1489, 1332, 1279, 1196, 1139, 1131, 1035, 960, 944, 884, 742, 713, 680cm^-1. HRMS (APCI, m/z): Calcd for C₁₅H₁₂N [M+ H]⁺ 206.0964, found 206.0973. 4.2.2 3-Amino-N-hydroxypyrazine-2-carboxamide (8) M.p. 198-200°C (Lit.²¹ 196°C), ¹H NMR (DMSO-d₆, 400MHz): δ_H 7.42 (brs, 3H, NH₂+OH), 7.76 (d, J=2.4Hz, 1H, ArH), 8.17 (d, J=2.4Hz, 1H, ArH), 9.43 (brs, 1H, NH). ¹³C NMR (DMSO-d₆, 100MHz): δ_C 126.3, 131.3, 146.8, 155.1, 163.6.

References:

Pan, Wan-Chen;Liu, Jian-Quan;Wang, Xiang-Shan [Tetrahedron,2018,p. 1468 - 1475]