1-METHYL-3-PROPYLPYRAZOLE-5-CARBOXYLIC ACID

1-METHYL-3-PROPYLPYRAZOLE-5-CARBOXYLIC ACID Property

Melting point:

150-154 °C

Boiling point:

330.3±30.0 °C(Predicted)

Density 

1.19±0.1 g/cm3(Predicted)

storage temp. 

Sealed in dry,Room Temperature

solubility 

Chloroform (Sightly), Methanol (Slightly)

form 

Solid

pka

3.10±0.25(Predicted)

color 

Off-White to Pale Beige

CAS DataBase Reference

139755-99-0(CAS DataBase Reference)

Safety

Risk Statements 

20/21/22

Safety Statements 

3/9-24/25-36/37

HazardClass 

IRRITANT

HS Code 

29331990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H290May be corrosive to metals

H302Harmful if swallowed

H314Causes severe skin burns and eye damage

Precautionary statements

P270Do not eat, drink or smoke when using this product.

P271Use only outdoors or in a well-ventilated area.

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

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

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

P310Immediately call a POISON CENTER or doctor/physician.

P330Rinse mouth.

P331Do NOT induce vomiting.

P363Wash contaminated clothing before reuse.

P390Absorb spillage to prevent material damage.

P402Store in a dry place.

P403+P233Store in a well-ventilated place. Keep container tightly closed.

1-METHYL-3-PROPYLPYRAZOLE-5-CARBOXYLIC ACID Chemical Properties,Usage,Production

Chemical Properties

White solid

Uses

Intermediate in the production of Sildenafil and respective analogs.

Synthesis

Preparation of Intermediate I-04a: Ethyl 1-methyl-3-n-propyl-pyrazole-5-carboxylate (11 g, 56.12 mmol) was dissolved in 6 M hydrochloric acid solution (121 mL) and heated to 100°C for overnight reaction. Upon completion of the reaction, the mixture was concentrated under vacuum and subsequently extracted with ethyl acetate (EA) and the organic layer was washed with water. Finally, the organic layer was concentrated in vacuum to afford the target product 1-methyl-3-propyl-1H-pyrazole-5-carboxylic acid (I-04a) (9.4 g, 98% yield).ESI-MS (M + 1): 169; calculated value C8H12N2O2: 168.1.

References

[1] Patent: WO2014/131855, 2014, A1. Location in patent: Page/Page column 80
[2] Patent: WO2016/20307, 2016, A1. Location in patent: Page/Page column 50
[3] Patent: US2008/194529, 2008, A1. Location in patent: Page/Page column 56-57
[4] Patent: WO2015/114647, 2015, A1. Location in patent: Page/Page column 46; 47
[5] Patent: US5250534, 1993, A