1-(3,4-Dimethoxyphenyl)-2-(methylsulfonyl)ethan-1-amine synthesis

Yield:1255909-25-1 89%

Reaction Conditions:

Stage #1: dimethylsulfonewith n-butyllithium in tetrahydrofuran at -10 - 5; for 1 h;Inert atmosphere;
Stage #2: veratronitrile in tetrahydrofuran; for 2 h;Inert atmosphere;Further stages;

Steps:

1.4 Step (4):

Dimethyl sulfone (7g) is dissolved in 70mL of anhydrous tetrahydrofuran,Nitrogen protection, stirring and cooling to below -10,Drop in n-butyl lithium (30mL, 2.5N),Keep the temperature below 5,After reacting for 1 hour,Drop into the intermediate M3 obtained in step (3)(10g dissolved in 20mLTHF),After incubating the reaction for 2 hours, add 3 g of sodium borohydride in three batches,Drop in 10 mL of acetic acid,React at room temperature for 12 hours,Add a drop of 2.5N sodium hydroxide aqueous solution to adjust the pH to 12,Raise the temperature to 60°C and react for 4 hours,Cool to room temperature,Add 300ml EA extraction,The organic phase was washed with water to neutrality and concentrated under reduced pressure to obtain a solid.Petroleum ether/ethyl acetate was recrystallized to obtain M4 (yield 89%).

References:

CN112876403,2021,A Location in patent:Paragraph 0031; 0042-0044