Ethyl 2-amino-4-methylthiophene-3-carboxylate

Ethyl 2-amino-4-methylthiophene-3-carboxylate (CAS 43088-42-2) is a strategically functionalized thiophene derivative engineered for heterocyclic construction and medicinal chemistry applications. 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 and thienopyridines. The ortho-like arrangement of the amino and ester groups facilitates efficient condensation cyclization with 1,3-dielectrophiles (e.g., formamidine acetate, urea derivatives), while the 4-methyl substituent provides electronic modulation and metabolic stability enhancement. This intermediate is particularly valuable for constructing kinase inhibitor cores, anti-inflammatory agents, and agrochemical actives where the thiophene bioisostere offers improved lipophilicity and π-stacking capabilities compared to benzene analogs. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to sulfur-containing heterocyclic architectures with defined substitution patterns.

Property

Product Name	Ethyl 2-amino-4-methylthiophene-3-carboxylate
CAS Number	43088-42-2
Chinese Name	2-氨基 -4-甲基噻吩 -3-羧酸乙酯
Synonyms	Ethyl 2-amino-4-methyl-3-thienecarboxylate; 2-Amino-4-methylthiophene-3-carboxylic acid ethyl ester; C₈H₁₁NO₂S heterocycle
Chinese Synonyms	2-氨基 -4-甲基 -3-噻吩羧酸乙酯; 氨基甲基噻吩羧酸酯; 2-氨基 -4-甲基噻吩 -3-甲酸乙酯
Molecular Formula	C₈H₁₁NO₂S
Molecular Weight	185.24 g/mol
Purity	≥ 98% (GC/HPLC area normalization)
Product Category	Pharmaceutical Intermediates / Thiophene Derivatives / Amino Ester Heterocycles
Appearance	Light yellow to Yellow to Orange Crystalline Powder or Solid
Melting Point	79-84°C
Storage Conditions	Store in a cool, dry, well-ventilated area away from light and moisture. Store at room temperature (recommended in a cool and dark place, <15°C). Keep container tightly closed. Protect from strong oxidizing agents to avoid sulfur oxidation.
Shelf Life	24 months under recommended storage conditions
Packaging	100g/bottle, 500g/bottle, 1kg/bottle, 5kg/drum, or customized according to customer requirements
Applications	Thienopyrimidine synthesis, kinase inhibitor scaffold development, anti-inflammatory drug intermediates, agrochemical active ingredient precursors, heterocyclic library synthesis via condensation cyclization
Reactivity	Suitable for condensation with 1,3-dielectrophiles (cyclization), ester hydrolysis to acid, amino group acylation/alkylation, electrophilic aromatic substitution at C5, and sulfur oxidation to sulfone/sulfoxide
Special Note	✅ Cyclization-Ready Scaffold—2-NH₂/3-COOEt motif enables rapid access to fused thienoheterocycles. 4-Methyl group enhances lipophilicity vs. unsubstituted analogs. Part of our thiophene building block series.