Overview and Chemical Properties

3-(Methoxycarbonyl)isothiazolidine 1,1-dioxide (Aladdin SKU: M997526) belongs to the sultam family of heterocyclic compounds. The isothiazolidine 1,1-dioxide ring system is a five-membered cyclic sulfonamide in which sulfur bears two oxygen atoms (as a sulfone), and nitrogen completes the ring. The methoxycarbonyl group at C-3 provides a handle for further chemical elaboration, including hydrolysis to the free carboxylic acid, transesterification, amide coupling, or Curtius rearrangement to access amines.

Sultam scaffolds are of significant interest in drug discovery because the SO₂NH motif mimics certain peptide bond geometries, improves aqueous solubility relative to purely carbocyclic analogues, and can act as a bioisostere for carboxamides or sulfonamides in bioactive molecules.

Materials and Safety Precautions

Materials required:

• 3-(Methoxycarbonyl)isothiazolidine 1,1-dioxide (M997526)
• Anhydrous solvents as appropriate (e.g., DMF, DMSO, DCM, THF, or MeOH depending on the reaction)
• Analytical balance (milligram precision)
• Inert atmosphere equipment (Schlenk line or glovebox) if moisture-sensitive conditions are required
• Personal protective equipment: lab coat, chemically resistant gloves, safety glasses

Safety precautions: Although specific GHS hazard data for M997526 should be confirmed from the current Safety Data Sheet (SDS) available from Aladdin Scientific, general precautions for cyclic sulfonamide reagents apply. Handle in a well-ventilated fume hood. Avoid inhalation of dust or aerosols. Wash hands thoroughly after handling. Store according to SDS recommendations, typically in a cool, dry place away from strong bases and oxidising agents.

Step-by-Step Protocol: Dissolution and Stock Solution Preparation

Step 1 – Equilibrate to room temperature. Remove the vial of M997526 from storage and allow it to equilibrate to room temperature before opening to minimise moisture condensation on the solid.

Step 2 – Weigh the reagent. Using a tared vessel on an analytical balance inside a fume hood, accurately weigh the required quantity of 3-(Methoxycarbonyl)isothiazolidine 1,1-dioxide.

Step 3 – Select an appropriate solvent. The compound is expected to dissolve in polar aprotic solvents (DMSO, DMF) and in halogenated solvents (DCM, chloroform). Solubility in aqueous media or protic solvents should be verified experimentally before use. Begin with DMSO for general stock solution preparation.

Step 4 – Prepare the stock solution. Add the weighed solid to a clean, dry vial. Add solvent in portions with gentle agitation (vortex or stirring) until complete dissolution is achieved. Confirm clarity of the solution visually before use.

Step 5 – Filter if necessary. If particulates remain, pass the solution through a 0.2 µm PTFE syringe filter.

Step 6 – Aliquot and store. Divide the stock solution into single-use aliquots under inert atmosphere if required. Store aliquots at –20 °C or as directed by the SDS. Record preparation date and concentration on each vial.

Note: Verify compatibility of M997526 with your specific reaction conditions prior to large-scale use. Consult the Aladdin SDS and current literature for additional guidance.

Typical Synthetic Applications

3-(Methoxycarbonyl)isothiazolidine 1,1-dioxide serves as a multifunctional building block in synthetic and medicinal chemistry:

• Ester hydrolysis: Treatment with aqueous base (e.g., LiOH in THF/water) cleaves the methyl ester to afford the corresponding carboxylic acid, which can be used in subsequent amide coupling reactions.
• Amide formation: Activation of the carboxylic acid form (after hydrolysis) with coupling reagents (e.g., HATU, EDC) allows installation of diverse amine partners to produce sultam-carboxamide hybrids.
• N-Functionalisation: The sulfonamide nitrogen can be alkylated or acylated under basic conditions to introduce additional diversity at the ring nitrogen.
• Ring-opening or rearrangement: Depending on conditions, the strained cyclic system may participate in ring-opening reactions to generate open-chain sulfonamide derivatives.

Note: Specific reaction conditions (temperature, equivalents, time) should be optimised for each transformation. The above applications are indicative based on the known reactivity of the isothiazolidine 1,1-dioxide scaffold; experimental validation is required.

Quality Control and Troubleshooting

Identity confirmation: Confirm the identity of M997526 by ¹H NMR and/or LC-MS prior to use in critical experiments. Key spectral features include signals attributable to the ring CH and CH₂ protons, the OCH₃ singlet (~3.8 ppm), and the NH proton of the sulfonamide.

Purity assessment: Use HPLC (reverse-phase, C18 column, UV detection at 210–220 nm) to assess purity. Consult the certificate of analysis (CoA) supplied with M997526 for the vendor-specified purity value.

Troubleshooting:

• Poor solubility: If the compound does not dissolve readily in DCM or THF, switch to DMSO or DMF. Gentle warming (40–50 °C) may assist dissolution; avoid prolonged heating.
• Unexpected colour: A yellow or brown discolouration may indicate partial degradation. If in doubt, re-confirm purity by HPLC before use.
• Low reaction yield: Ensure anhydrous conditions if moisture-sensitive steps are involved. Check the stoichiometry and base loading. Consult the literature on isothiazolidine 1,1-dioxide reactivity for guidance.