Hydrochloric Acid → rac-Methyl 5,5,6,6,6-pentafluoronorleucinate hydrochloride

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Under argon, 132 g (521.0 mmol) of methyl N-(diphenylmethylene)glycinate [described in: WO2010/123792 A1, 2010, 11-13; additionally: commercially available] were initially charged in 1000 ml of THF (anhydrous) and cooled to −40° C. 625.2 ml (625.2 mmol) of bis(trimethylsilyl)lithium amide (1 M in THF) were added dropwise over 30 min. After 10 min, the cooling bath was replaced by a water/ice bath, and the internal temperature was allowed to increase to 0° C. over a period of 35 min. At 0° C., 192.86 g (651.25 mmol) of 3,3,4,4,4-pentafluorobutyl trifluoromethanesulphonate from Example 132A, dissolved in 400 ml of THF, were added dropwise to the reaction solution. After 10 min, the cooling bath was removed and the mixture was stirred at RT for 3 days. The reaction mixture was then cooled to 0° C., and 410 ml (1.33 mol) of 3 N hydrochloric acid were added dropwise. The cooling bath was removed and the reaction solution was stirred at RT for 2 hours. The mixture was then concentrated. This gave 141.5 g of the target compound as a crude mixture which was used without any further purification for the next step.

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