Methanesulfonic Acid → (2S)-3,3,3-Trifluoro-2-methylpropane-1,2-diamine

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Reaction Steps

A mixture of 10.50 g (70 mmol) of (R)-2-((S)-1-aminomethyl-2,2,2-trifluoro-1-methylethylamino)-2-phenylethanol in methanol, 4.5 mL (68 mmol) of methanesulfonic acid and 1.50 g of Pd(OH)2/C (20% w/w) is hydrogenated at 25° C. in an autoclave, under a hydrogen pressure of 5 bar, for 24 hours. The mixture obtained is then filtered and the filtrate is evaporated to dryness. The oil obtained is taken up in 3 M hydrochloric acid solution (42 mL). The mixture obtained is extracted with ethyl ether. Ethyl ether and 15 mL of 35% sodium hydroxide are then added to the aqueous phase, to pH 12. The aqueous phase is then separated out by settling and extracted with 3 times 200 mL of ethyl ether. The organic phases are combined, dried over magnesium sulfate, filtered and then concentrated under vacuum to give 4.50 g of (S)-3,3,3-trifluoro-2-methylpropane-1,2-diamine in the form of a pale yellow oil, the characteristics of which are as follows:

Provenance & Evidence