376584-63-3 | 1H-Pyrazole-3-boronic acid

Packsize	Purity	Availability	Price	Discounted Price
250mg	97%	in stock	$8.00	$5.00
1g	97%	in stock	$8.00	$6.00
5g	97%	in stock	$14.00	$10.00
10g	97%	in stock	$25.00	$18.00
25g	97%	in stock	$59.00	$42.00

Description

• Catalog Number: AB78716
• Chemical Name: 1H-Pyrazole-3-boronic acid
• CAS Number: 376584-63-3
• Molecular Formula: C3H5BN2O2
• Molecular Weight: 111.895
• MDL Number: MFCD11044442
• SMILES: OB(c1cc[nH]n1)O

Computed Properties

• Complexity: 79.7
• Covalently-Bonded Unit Count: 1
• Heavy Atom Count: 8
• Hydrogen Bond Acceptor Count: 3
• Hydrogen Bond Donor Count: 3
• Rotatable Bond Count: 1

Upstream Synthesis Route

The upstream synthesis of 1H-Pyrazole-3-boronic acid typically begins with the preparation of the pyrazole ring, followed by the introduction of the boronic acid functionality. Here is a concise, stepwise approach to the synthesis:

1. **Synthesis of Pyrazole Ring**:
- Start with the condensation of a hydrazine derivative with a suitable beta-keto ester or beta-diketone in the presence of acid or base catalyst to form a pyrazole precursor.
- Consider the use of hydrazine hydrate and 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one as a basis for the pyrazole structure required.

2. **Functionalization at the 3-position**:
- Perform a halogenation (usually bromination) at the C-3 position of the pyrazole ring, where the halogen (Br) acts as a good leaving group for the subsequent boronation step.

3. **Introduction of Boronic Acid**:
- Proceed with a borylation reaction, typically facilitated by a metal-catalyzed (such as palladium-catalyzed) cross-coupling reaction, using a boronic acid or boronic ester derivative, such as bis(pinacolato)diboron, in the presence of a suitable catalyst and ligands.
- During this step, the C-Br bond is replaced by a C-B bond to introduce the boronic acid functionality.
- Utilize an aqueous workup to hydrolyze any boronic esters to the corresponding boronic acids, if necessary.

4. **Purification**:
- Purify the resultant 1H-Pyrazole-3-boronic acid through crystallization or chromatography to achieve the desired product with high purity.

This synthesis route provides a general pathway to 1H-Pyrazole-3-boronic acid. However, optimization of reaction conditions such as temperature, solvent, and catalysts might be required, depending on the specific substrates and reagents used. It is critical for the chemist to monitor reactions closely and verify structures at each step via appropriate analytical techniques like NMR, GC-MS, or HPLC.

Literature

• Inhibitor scaffold for the histone lysine demethylase KDM4C (JMJD2C).

  Bioorganic & medicinal chemistry letters 20120915