Ethyl 2-amino-4-methylthiazole-5-carboxylate

China [CN]

1. Appearance and Properties

At room temperature and pressure, it is a white to off-white crystalline powder. High-purity products appear as white needle-shaped crystals, which may tinge with a slight yellowish hue when the impurity content is high. It has no noticeable pungent odor and has good fluidity in its solid state, resisting agglomeration.

2. Melting Point and Solubility

Melting point: Typical range: 148–152°C (the pure product has a narrow melting range, typically 150–151°C; impurities lower the melting point, extending the range to 3–5°C). Melting point measurement can be used to preliminarily assess purity. Solubility:

Freely soluble in polar organic solvents such as methanol, ethanol, ethyl acetate, dichloromethane, and N,N-dimethylformamide (DMF), with a solubility of 10–15 g/100 mL in ethanol at room temperature.

Slightly soluble in moderately polar solvents such as ether and toluene.

Poorly soluble in water (solubility <0.5 g/100 mL at room temperature) and non-polar solvents such as n-hexane and petroleum ether.

The ester group can be hydrolyzed to a carboxylate salt under alkaline conditions (such as aqueous NaOH), significantly increasing its water solubility and facilitating post-processing in aqueous phase reactions.

3. Stability and Chemical Activity

Stability:

Stable at room temperature, in a dry place, and protected from light. It can be stored sealed for 12–24 months.

Avoid contact with strong oxidants (such as potassium permanganate and hydrogen peroxide) to prevent oxidation of the amino group.

High temperatures (>200°C) may cause thiazole ring opening or ester group decomposition, so reaction temperatures below 150°C are recommended.