Methyl 2-amino-4-methylthiophene-3-carboxylate

Methyl 2-amino-4-methylthiophene-3-carboxylate (CAS 4651-98-3) is a high-purity, cyclization-ready thiophene building block engineered for kinase inhibitor synthesis, thienopyrimidine construction, and medicinal chemistry applications. As the methyl ester analog of the ethyl counterpart (CAS 43088-42-2), this molecule integrates a 2-amino-3-ester substitution pattern on a 4-methylthiophene core—a privileged scaffold for synthesizing fused thienoheterocycles such as thieno[2,3-d]pyrimidines, thienopyridines, and other sulfur-containing heterocycles. The ortho-like arrangement of the amino and ester groups facilitates efficient condensation cyclization with 1,3-dielectrophiles, enabling rapid access to diverse fused ring systems. The methyl ester moiety offers slightly reduced lipophilicity compared to the ethyl analog, potentially enhancing aqueous solubility during early-stage screening and formulation development. This intermediate is particularly valuable for constructing kinase inhibitor cores, anti-inflammatory agents, and agrochemical actives where the thiophene bioisostere offers improved metabolic stability over phenyl or pyridine analogs. Manufactured under controlled conditions, it supports drug discovery programs requiring modular access to sulfur-containing heterocyclic architectures with defined ester chain lengths and tunable physicochemical properties.