Methyl 5-Formyl-2-Methoxybenzoate: Properties & Applications

Methyl 5-formyl-2-methoxybenzoate is a bifunctional aromatic building block bearing both an aldehyde and a methyl ester group on a methoxy-substituted benzene ring, making it a versatile intermediate for organic synthesis and medicinal chemistry research.

Chemical Name

Methyl 5-formyl-2-methoxybenzoate

Molecular Formula

C₁₀H₁₀O₄

Molecular Weight

194.18 g/mol

CAS Number

Needs review — not confirmed in source material

Key Functional Groups

Aldehyde (–CHO), Methyl ester (–COOCH₃), Methoxy (–OCH₃)

SKU

M195060

Supplier

Aladdin Scientific

Chemical Structure and Key Properties

Methyl 5-formyl-2-methoxybenzoate (molecular formula C₁₀H₁₀O₄, molecular weight approximately 194.18 g/mol) is an aromatic compound featuring three distinct functional groups on a single benzene ring: an aldehyde group at the 5-position, a methoxy group at the 2-position, and a methyl ester at the 1-position (carboxylate). This combination of electron-withdrawing (ester, aldehyde) and electron-donating (methoxy) substituents creates a polarized ring system with rich reactivity. The compound is typically a solid at room temperature, and like most aromatic aldehydes, it should be stored away from strong oxidizers, bases, and reducing agents to preserve purity. Its relatively low molecular weight and defined substitution pattern make it straightforward to characterize by standard spectroscopic techniques including ¹H NMR, ¹³C NMR, and IR spectroscopy.

Synthesis Utility and Role as a Building Block

The defining feature of Methyl 5-formyl-2-methoxybenzoate as a synthetic reagent is the presence of two independently addressable electrophilic sites — the aldehyde carbon and the ester carbonyl — alongside the nucleophilically activating methoxy group. This multifunctionality enables its use in a wide variety of transformations commonly employed in medicinal chemistry and materials science.

The aldehyde group readily participates in condensation reactions such as Knoevenagel condensations, reductive aminations, Wittig and Horner–Wadsworth–Emmons olefinations, and imine (Schiff base) formation with primary amines. These reactions are routinely used to introduce carbon–carbon double bonds or nitrogen-containing linkages into target molecules. The methyl ester, meanwhile, can be selectively saponified to the free carboxylic acid, reduced to the alcohol with hydride reagents, or converted to amides, enabling diverse downstream elaboration. The methoxy group can, under appropriate conditions, participate in demethylation to reveal a phenol, or direct electrophilic aromatic substitution. Together, these functional handles make this compound a genuinely versatile bifunctional building block in multi-step synthesis.

Applications in Medicinal Chemistry and Drug Discovery

Bifunctional aromatic aldehydes bearing ester or methoxy groups are widely represented in the synthetic intermediates used to access pharmacologically relevant scaffolds. Methyl 5-formyl-2-methoxybenzoate is particularly useful for constructing benzaldehyde-derived heterocycles, including isoquinolines, benzoxazoles, benzimidazoles, and related ring systems, through condensation of the aldehyde with suitable nitrogen or oxygen dinucleophiles.

The methoxy-substituted aromatic motif is also prevalent in bioactive natural products and approved drugs, lending relevance to synthetic targets derived from this building block. Researchers working on structure–activity relationship (SAR) studies can exploit the independent reactivity of the aldehyde and ester to introduce structural diversity at two separate positions within a single synthetic step or in sequential transformations. The compound may also serve as a precursor in the synthesis of fluorescent probes, ligands for metal-catalyzed reactions, or monomers for functional polymers, broadening its utility beyond traditional small-molecule drug discovery.

Handling, Storage, and Laboratory Safety

As with most aromatic aldehyde-containing compounds, Methyl 5-formyl-2-methoxybenzoate should be handled with standard laboratory precautions. Personnel should wear appropriate personal protective equipment including gloves, safety glasses, and lab coat. Work should be performed in a well-ventilated area or fume hood to minimize inhalation exposure to fine particulates or vapors.

The compound should be stored in a tightly sealed container, protected from light, moisture, and incompatible materials such as strong oxidizing agents and strong bases, which can react with both the aldehyde and the ester functionalities. Storage at cool, dry conditions (typically room temperature to slightly below, as specified on the product certificate of analysis) helps maintain long-term stability and purity. Researchers are advised to consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for M195060 for complete hazard information, first-aid measures, and disposal guidance before use.

Frequently asked questions

What makes Methyl 5-formyl-2-methoxybenzoate useful as a synthetic intermediate?

Its value lies in the simultaneous presence of three functional groups — an aldehyde, a methyl ester, and a methoxy group — on a single aromatic ring. The aldehyde and ester can be selectively and independently transformed, enabling efficient access to structurally complex targets in fewer synthetic steps.

Can the aldehyde and ester groups in this compound be reacted independently?

Yes. Under carefully controlled conditions, the aldehyde group can be selectively engaged in condensations, reductive aminations, or olefination reactions, while the methyl ester remains intact. Conversely, the ester can be saponified or reduced selectively without disturbing the aldehyde under appropriate mild conditions, although careful optimization is required to achieve high chemoselectivity.

What types of heterocyclic compounds can be synthesized using Methyl 5-formyl-2-methoxybenzoate?

The aldehyde functionality can be employed to construct a range of nitrogen- and oxygen-containing heterocycles, including imines (Schiff bases), benzimidazoles, benzoxazoles, and isoquinoline frameworks, through condensation with appropriate dinucleophiles. The methoxy and ester groups provide additional handles for further ring elaboration or functionalization.

How should Methyl 5-formyl-2-methoxybenzoate be stored to maintain purity?

The compound should be stored in a tightly sealed container under cool, dry, and dark conditions, away from strong oxidizers, strong bases, and moisture. Always refer to the product SDS and certificate of analysis from Aladdin Scientific (SKU M195060) for specific storage temperature recommendations.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. General reference for aldehyde and ester reactivity.
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry. Oxford University Press. Reference for functional group transformations and selectivity.
3. Aladdin Scientific. Product page for Methyl 5-formyl-2-methoxybenzoate, SKU M195060.

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