1H-Pyrazole-1-carboxamidine hydrochloride

Chemical Properties

white to light yellow crystals or crystalline

Uses

1H-Pyrazole-1-carboxamidine hydrochloride is a stable and versatile reagent for the efficient and chemically specific guanylation of sterically unhindered primary and secondary aliphatic amines under mild conditions. 1H-Pyrazole-1-carboxamidine hydrochloride is a useful reagent in peptide synthesis

Uses

1H-Pyrazole-1-carboxamidine hydrochloride may be used in the following studies: Preparation of guanidylated hollow fiber membranes. Guanylation of amines and in peptide synthesis. Synthesis of bis-guanidinium-cholesterol derivatives.

General Description

1H-Pyrazole-1-carboxamidine hydrochloride, a pyrazole derivative, is a heterocyclic compound. It is widely used in drug syntheses studies. Pyrazole ring forms the main core of various nonsteroidal anti-inflammatory drugs (NSAIDs) and antihypertensive drugs.

Synthesis

Pyrazole (1.634 g, 24 mmol) and cyanamide (1 g, 24 mmol) were dissolved in 1,4-dioxane (24 mL), followed by the addition of 4 M hydrochloric acid (6 mL) to the 1,4-dioxane solution. The reaction mixture was stirred under reflux conditions for 1 hour. Upon completion of the reaction, the reaction mixture was placed in an ice-water bath and the product was induced to recrystallize by the addition of ether. The yield of the final product was 43%.

References

[1] Journal of Organic Chemistry, 1992, vol. 57, # 8, p. 2497 - 2502
[2] Organic Letters, 2004, vol. 6, # 26, p. 4925 - 4927
[3] Patent: KR101808950, 2017, B1. Location in patent: Paragraph 0233-0236
[4] Bioorganic and Medicinal Chemistry Letters, 2000, vol. 10, # 24, p. 2771 - 2774
[5] Journal of Medicinal Chemistry, 2005, vol. 48, # 3, p. 812 - 820