N-BOC-ALPHA-METHYL-L-PROLINE

N-BOC-ALPHA-METHYL-L-PROLINE Property

Boiling point:

337.8±35.0 °C(Predicted)

Density 

1.160

storage temp. 

2-8°C

pka

4.20±0.20(Predicted)

form 

Solid

color 

White to off-white

InChI

InChI=1S/C11H19NO4/c1-10(2,3)16-9(15)12-7-5-6-11(12,4)8(13)14/h5-7H2,1-4H3,(H,13,14)/t11-/m0/s1

InChIKey

YQXRKJHVAUKXRN-NSHDSACASA-N

SMILES

N1(C(OC(C)(C)C)=O)CCC[C@@]1(C)C(O)=O

Safety

Hazard Codes 

Xn

Risk Statements 

22

HS Code 

2933998090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H317May cause an allergic skin reaction

Precautionary statements

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

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P272Contaminated work clothing should not be allowed out of the workplace.

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

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

P321Specific treatment (see … on this label).

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P333+P313IF SKIN irritation or rash occurs: Get medical advice/attention.

P362Take off contaminated clothing and wash before reuse.

P363Wash contaminated clothing before reuse.

P501Dispose of contents/container to..…

N-BOC-ALPHA-METHYL-L-PROLINE Chemical Properties,Usage,Production

Uses

N-Boc-2-methyl-L-proline is used as pharmaceutical intermediate.

Synthesis

(S)-2-methylpyrrolidine-2-carboxylic acid hydrochloride (23; 82.5 g, 498 mmol) was dissolved in a solvent mixture of acetonitrile/water (1:1, 1000 mL) and triethylamine (TEA, 210 mL, 1490 mmol) was added. Subsequently, di-tert-butyl dicarbonate (Boc2O, 120 g, 548 mmol) dissolved in acetonitrile (200 mL) was added. The reaction mixture was stirred at room temperature for 3 hours. The organic solvent was removed by evaporation under reduced pressure and 2M aqueous sodium hydroxide (300 mL) was added to the residue. The aqueous phase was extracted with ether (Et2O, 400 mL), cooled to 10 °C and the pH was adjusted to 5-6 by slow addition of 25% aqueous hydrochloric acid. 1M aqueous hydrochloric acid was then carefully added to pH=2 and the product precipitated. The precipitate was collected by filtration, washed with water (300 mL), and dried under high vacuum to give (S)-1-(tert-butoxycarbonyl)-2-methylpyrrolidine-2-carboxylic acid (24, 90.7 g) as a light gray solid. lc-MS: tR = 0.63 min; [M + H]+ = 230.24.

References

[1] Tetrahedron Letters, 1996, vol. 37, # 20, p. 3441 - 3444
[2] Patent: WO2008/8551, 2008, A2. Location in patent: Page/Page column 34
[3] Patent: US2010/197654, 2010, A1. Location in patent: Page/Page column 57
[4] Organic Letters, 2011, vol. 13, # 22, p. 5964 - 5967
[5] Patent: WO2013/182972, 2013, A1. Location in patent: Page/Page column 110