Ethyl 5-amino-1h-pyrazole-3-carboxylate

Ethyl 5-amino-1H-pyrazole-3-carboxylate (CAS 105434-90-0) is a strategically functionalized pyrazole building block for heterocyclic diversification in medicinal chemistry and agrochemical development. This molecule integrates three orthogonal reactive handles: a C5-amino group enabling electrophilic substitution or condensation cyclization, a C3-ethyl ester suitable for hydrolysis or amide coupling, and a 1H-pyrazole core that serves as a privileged scaffold in kinase inhibitors, anti-inflammatory agents, and CNS modulators. The electron-rich pyrazole ring—combined with the activating amino substituent—facilitates regioselective functionalization at C4, while the ester moiety provides a versatile anchor for peptide coupling or prodrug design. This intermediate is particularly valuable for constructing fused heterocyclic systems (e.g., pyrazolo[1,5-a]pyrimidines), kinase inhibitor cores targeting ATP-binding pockets, and agrochemical actives where the aminopyrazole motif enhances target selectivity. Manufactured under controlled conditions, it supports drug discovery programs requiring modular access to nitrogen-rich heterocyclic architectures.