(S)-(-)-2-Hydroxy-3,3-dimethylbutyric acid

(S)-(-)-2-Hydroxy-3,3-dimethylbutyric acid Property

Melting point:

48-50 °C (lit.)

alpha 

-62 º (C=1 IN H2O)

Boiling point:

242.4±13.0 °C(Predicted)

Density 

1.100±0.06 g/cm3(Predicted)

storage temp. 

Sealed in dry,Room Temperature

form 

solid

pka

3.91±0.27(Predicted)

optical activity

[α]20/D 64±5°, c = 1 in H2O/molybdate

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

3

HS Code 

29181998

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

(S)-(-)-2-Hydroxy-3,3-dimethylbutyric acid Chemical Properties,Usage,Production

Uses

Building block for chiral tert-butyl substituted α-lactams, diols, and α-hydroxyketones.

Synthesis

General procedure for the synthesis of (S)-2-hydroxy-3,3-dimethylbutanoic acid from L-tert-leucine: 3,3-dimethylbutanoic acid (1 g, 7.5 mmol) was dissolved in an aqueous solution of 1 M sulfuric acid (15 ml) and cooled to 0°C. An aqueous solution (8 ml) of sodium nitrite (1.0 g, 15 mmol) was slowly added while keeping the reaction temperature below 5°C. The reaction mixture was stirred at the same temperature overnight. After completion of the reaction, it was treated with a saturated solution of ammonium sulfate followed by extraction with ether (5 x 25 ml). The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford (S)-2-hydroxy-3,3-dimethylbutyric acid (0.27 g, 67% yield) as a colorless oil, which crystallized after standing. The product was confirmed by 1H NMR (400 MHz, CD3OD): δ 3.41 (s, 1H), 1.25 (s, 9H). LCMS analysis showed m/z 133.2 [M + H]+ with a retention time Tr = 0.39 min (using a Gemini 5u C18 150 × 4.60 mm 5 µm column at a flow rate of 3.5 ml/min with gradient elution). conditions: 5-100% acetonitrile/water with 0.1% acetic acid modifier).

References

[1] Liebigs Annalen der Chemie, 1982, vol. No. 11, p. 1952 - 1970
[2] Journal of Organic Chemistry, 1991, vol. 56, # 7, p. 2499 - 2506
[3] Patent: WO2013/185093, 2013, A1. Location in patent: Page/Page column 261
[4] Journal of Organic Chemistry, 2017, vol. 82, # 9, p. 4949 - 4957
[5] Bioorganic and Medicinal Chemistry Letters, 2005, vol. 15, # 15, p. 3540 - 3546