Isoquinoline, 5-azido- (9CI) synthesis

Yield:43101-10-6 96.9%

Reaction Conditions:

Stage #1: isoquinolin-5-ylaminewith sulfuric acid in water at 0; for 0.0833333 h;
Stage #2: with sodium azide in water at 20; for 0.166667 h;

Steps:

1 Synthesis of INT 13-b

A mixture of isoquinolin-5 -amine (1.4 g, 9.71 mmol) in sulfuric acid (2.5 mL) and H2O (7 mL) was cooled to 0 °C and sodium nitrite (800 mg, 11.6 mmol) in H2O (5 mL ) was added. The mixture was stirred at 0 °C for 5 min. Then NaN3 (631 mg, 9.71 mmol) in H2O (5 mL) was added and the reaction mixture was stirred at 20 °C for 10 min. The reaction mixture was neutralized with NH3.H2O. The solid was collected by filtration to give 5-azidoisoquinoline (1.60 g, 96.9% yield) as a solid which was used for next step directly m/z: [M + H]⁺ Calcd for C9H6N4 171.1; Found 170.9.

References:

WO2021/138298,2021,A1 Location in patent:Paragraph 00120; 00178