2-tert-Butyl 7-methyl 3,4-dihydroisoquinoline-2,7(1H)-dicarboxylate synthesis

Yield:960305-54-8 95.5 %

Reaction Conditions:

with potassium carbonate at 20;

Steps:

62.A Step A: Synthesis of methyl 2-(tert-Butoxycarbonyl)-1,2,3,4-tetrahydroisoquinoline-7-carboxylate

At room temperature, 2-(tert-Butoxycarbonyl)-1,2,3,4-tetrahydroisoquinoline-7-carboxylic acid (300.0 mg, 1.1 mmol) is dissolved in N,N-dimethylformamide (5 ml) solution, anhydrous potassium carbonate (300.0 mg, 2.2 mmol) and methyl iodide (307.2 mg, 2.2 mmol) are added for 2 h at room temperature. At the end of the reaction, saturated ammonium chloride aqueous solution (10 ml) was added to quench, ethyl acetate (100 ml) diluted, washed with 1 mole of hydrochloric acid per liter (20 ml× 3 times), saturated saline (20 ml × 1 time), dried anhydrous sodium sulfate, concentrated. The resulting residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 300.0 mg of methyl 2-(tert-butoxycarbonyl)-1,2,3,4-tetrahydroisoquinoline-7-carboxylate (yield 95.5%).

References:

CN115594669,2023,A Location in patent:Paragraph 1247-1253