Preparative Method for Asymmetric Synthesis of (S)-2-Amino-4,4,4-trifluorobutanoic Acid
Abstract
:1. Introduction
2. Results and Discussion
3. Materials and Methods
3.1. General Methods
3.2. Alkylation of (S)-6 with ICH2CF3
3.2.1. 80 g Scale Reaction
3.2.2. 250 g Scale Reaction
3.3. Disassembly of Major Diastereomer (S)(2S)-7 and Preparation of (S)-12
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Conflicts of Interest
References
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Sample Availability: Not available. |
Entry | Scale | Conditions | Results |
---|---|---|---|
1 | (S)-6 80 g | ICH2CF3 (1.05 eq. 29.32 g), KOH (96.8% assay, 1.05 eq. 8.14 g), MeOH (0.9 v, 72 mL), DMF (10 v, 800 mL), rt (room temperature), 1 h | (S)(2S)-7 73.7 g, 81.1% yield, >99% de (diasteromeric excess) |
2 | (S)-6 250 g | ICH2CF3 (1.05 eq. 91.61 g), KOH (96.8% assay, 1.05 eq. 25.42 g), MeOH (0.9 v, 225 mL), DMF (10 v, 2500 mL), rt, 1 h | (S)(2S)-7 229.1 g, 80.7% yield, 99.9% de |
3 | (S)-6 250 g | ICH2CF3 (1.05 eq. 91.61 g), KOH (96.8% assay, 1.05 eq. 25.42 g), MeOH (0.9 v, 225 mL), DMF (10 v, 2500 mL), rt, 1 h | (S)(2S)-7 228.5 g, 80.4% yield, >99% de |
Entry | (S)(2S)-7 | Conditions | (S)-12 |
---|---|---|---|
1 | 10 g | 6N HCl (5 eq. 12.2 mL), DME (2 v, 20 mL), 50 °C, 1 h added H2O (2 v, 20 mL), 30 °C, 2 h then EDTA•2Na (1.02 eq. 5.55 g), 48% NaOH (4.2 eq. 5.1 g) Na2CO3 (1.3 eq. 2.02 g), Fmoc-OSu (1 eq. 4.94 g) MeCN (4 v, 9.2 mL), rt, 3 h | 4.26 g, 76.7% yield 99.0% ee (enantiomeric excess) |
2 | 220 g | 6N HCl (5 eq. 268 mL), DME (2 v, 440 mL), 50 °C, 1 h added H2O (2 v, 440 mL), 30 °C, 2 h then EDTA•2Na (1.02 eq. 122.2 g), 48% NaOH (5.4 eq. 143.6 g) Na2CO3 (1.3 eq. 44.35 g), Fmoc-OSu (1 eq. 108.57 g) MeCN (4 v, 200 mL), rt, 4 h | 92.7 g, 75.9% yield 98.8% ee |
3 | 220 g | 6N HCl (5 eq. 268 mL), DME (2 v, 440 mL), 50 °C, 1 h added H2O (2 v, 440 mL), 30 °C, 1.5 h then EDTA•2Na (1.02 eq. 122.2 g), 48% NaOH (5.2 eq. 138 g) Na2CO3 (1.3 eq. 44.35 g), Fmoc-OSu (1 eq. 108.57 g) MeCN (4 v, 200 mL), rt, 4 h | 99.5 g, 81.5% yield 98.4% ee |
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Han, J.; Takeda, R.; Liu, X.; Konno, H.; Abe, H.; Hiramatsu, T.; Moriwaki, H.; Soloshonok, V.A. Preparative Method for Asymmetric Synthesis of (S)-2-Amino-4,4,4-trifluorobutanoic Acid. Molecules 2019, 24, 4521. https://doi.org/10.3390/molecules24244521
Han J, Takeda R, Liu X, Konno H, Abe H, Hiramatsu T, Moriwaki H, Soloshonok VA. Preparative Method for Asymmetric Synthesis of (S)-2-Amino-4,4,4-trifluorobutanoic Acid. Molecules. 2019; 24(24):4521. https://doi.org/10.3390/molecules24244521
Chicago/Turabian StyleHan, Jianlin, Ryosuke Takeda, Xinyi Liu, Hiroyuki Konno, Hidenori Abe, Takahiro Hiramatsu, Hiroki Moriwaki, and Vadim A. Soloshonok. 2019. "Preparative Method for Asymmetric Synthesis of (S)-2-Amino-4,4,4-trifluorobutanoic Acid" Molecules 24, no. 24: 4521. https://doi.org/10.3390/molecules24244521