Hydrochloric Acid → N-Ethyl 5-chloro-2-(2-methylprop-2-en-1-yloxy)benzylamine

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Reaction Conditions

Reaction Steps

A mixture of 5-chlorosalicylaldehyde (25.0 g, 0.16 mol), anhydrous potassium carbonate (70.0 g, 0.5 mol), methallyl chloride (27.0 ml, 0.27 mol) and N-methylpyrrolidinone (250 ml) was stirred under reflux condenser at 60-70° C. for 16 hours. The mixture was cooled to 20° C. and treated cautiously with a solution of ethyl amine hydrochloride (40.0 g, 0.49 mol) in 200 ml methanol (frothing occurs). After complete addition the mixture was stirred for 1 hour at 20° C., then treated portionwise with sodium borohydride (4.6 g, 0.12 mol) and small aliquots (~1.0 ml) of ether to reduce frothing. The mixture was stirred for 1 hour at 20° C. and the boron-amine complex decomposed by cautious addition of 6N HCl (200 ml), cooling as necessary. The mixture was Stirred for 1 hour at 20° C., then basified with 2N NaOH to pH10 and extracted with dichloromethane (3×250 ml). The combined organic extracts were washed with water (3×250 ml), dried over anhydrous magnesium sulphate, filtered and evaporated to give a brown oil, which was dissolved in isopropanol (200 ml). Concentrated hydrochloric acid (36% w/v, 10 ml) was added with stirring and the solution cooled at 5° C. for 2 hours, white crystalline needles formed, which were filtered off, washed with isopropanol and ether to give the title compound as the hydrochloride salt (18.0 g, 41%).

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