Yield:40171-87-7 50%

Reaction Conditions:

Stage #1: 4-methyl-benzaldehyde;ethanolamine in methanol at 80; for 4 h;
Stage #2: with hydrogenchloride;sodium cyanoborohydride in water at 0 - 20; pH=3 - 4; for 2 h;

Steps:

1 Preparation of N- (4-methylbenzyl) ethanolamine (II-15)

P-Toluene aldehyde (1 g, 8.32 mmol)And dissolved in anhydrous methanol. Ethanolamine (0.53 g, 8.74 mmol) was added thereto, followed by reflux stirring at 80 ° C for 4 hours.After confirming the reaction using thin film chromatography, the temperature was lowered to 0 ° C and the pH was adjusted to 3-4 by adding hydrochloric acid.Sodium cyanoborohydride (1.1 g, 16.65 mmol) was added slowly and the mixture was stirred at room temperature for 2 hours.The reaction was confirmed by thin membrane chromatography and then fractionated using diethyl ether and water.Then, the aqueous layer was adjusted to pH 10 with an aqueous solution of sodium hydroxide, and the dichloromethane solution was extracted with dichloromethane and water. The water was removed using magnesium sulfate, and the solvent was removed using a rotary evaporator Respectively.The residue was purified using silica gel column chromatography with ethyl acetate: n-hexane (1: 1) to give the title compound (II-15) as a yellow liquid (0.68 g, 50%).

References:

KR101484977,2015,B1 Location in patent:Paragraph 0079; 0080