(S)-(+)-2-Methylpiperazine

(S)-(+)-2-Methylpiperazine Property

Melting point:

91-93 °C(lit.)

Boiling point:

155-156 °C

alpha 

13.5 º (c=1, toluene)

Density 

0.9305 (estimate)

refractive index 

1.4378 (estimate)

Flash point:

149 °F

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

form 

Crystalline Powder, Crystals and/or Chunks

pka

9.31±0.40(Predicted)

color 

White to yellow

optical activity

[α]20/D +6.8°, c = 1 in ethanol

Water Solubility 

soluble

Sensitive 

Air Sensitive & Hygroscopic

BRN 

3647995

InChIKey

JOMNTHCQHJPVAZ-YFKPBYRVSA-N

CAS DataBase Reference

74879-18-8(CAS DataBase Reference)

Safety

Hazard Codes 

F,Xi,C

Risk Statements 

11-36/37/38-34

Safety Statements 

16-26-36/37/39-45-36

RIDADR 

UN 1325 4.1/PG 2

WGK Germany 

3

RTECS 

TM1225020

HazardClass 

4.1

PackingGroup 

III

HS Code 

29335990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H228Flammable solid

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

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-Methylpiperazine Chemical Properties,Usage,Production

Chemical Properties

white to yellow crystalline powder or chunks

Uses

Valuable synthon for quinoline antibacterials.

Synthesis

General procedure for the synthesis of (R)-(-)-2-methylpiperazine and (S)-2-methylpiperazine from 2-methylpiperazine: 1. In a 2L four-necked flask equipped with a thermometer, a vacuum stirrer and a cooling tube, 270 g (1.8 mol) of L-tartaric acid, 108 g (1.8 mol) of acetic acid and 270 g of water were added and stirred until completely dissolved. 2. add (±)-2-methylpiperazine 300 g (3.0 mol) and water 300 g. Heat to 85 °C or higher until completely dissolved. 3. cool to 68-74°C, add diastereomerically precipitated crystals of (R)-2-methylpiperazine and L-tartaric acid and age for 1 hour. 4. cooled to 12-18 °C over 5 h and filtered to obtain 440 g of wet biomass (diastereomeric salt) with a liquid content of 22.7 wt% and an optical purity of 92.3% ee. 5. 644 g of water and 440 g of the resulting crystals ((R)-2-methylpiperazine pure content = 132 g) were added to a 2L four-neck flask, followed by 162 g (2.2 mol) of calcium hydroxide, heated to 80 °C, and aged for 5 hours. 6. Cooled to 25 °C and filtered to give 586 g of crystals (mainly calcium L-tartrate) and 660 g of filtrate (containing 130 g of (R)-2-methylpiperazine). 7. The filtrate was concentrated under reduced pressure to a (R)-2-methylpiperazine concentration of 30%, 356 g of toluene was added, and the water was removed by azeotropic boiling by heating to 84-87 °C. 8. 212 g of toluene was distilled under reduced pressure, cooled to 47 °C, 0.01 g of (R)-2-methylpiperazine crystal seed was added and aged for 1 hour. 9. cooled to 5 °C, aged for 2 h, filtered and dried under vacuum to give 45 g of (R)-2-methylpiperazine crystals (chemical purity 100%, optical purity 99.5% ee). 10. For the synthesis of (S)-2-methylpiperazine, a similar procedure was used but with (S)-2-methylpiperazine as starting material, resulting in 66.8 g of (S)-2-methylpiperazine crystals (chemical purity 99.9%, optical purity 80.0%ee).

References

[1] Patent: JP2016/37495, 2016, A. Location in patent: Paragraph 0046-0052