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Chemical product profile

HONGKUN / PRODUCT DIRECTORY

Isobutyl (S)-2-chloropropionate | CAS 83261-15-8

A chiral alpha-chloro ester with a branched isobutyl group, documented in optically active chloropropionate chemistry where the ester identity and opposite-enantiomer content must both match the intended synthesis.

CAS83261-15-8
Molecular formulaC7H13ClO2
Molecular weight164.63 g/mol

Product overview

An isobutyl group and an S-configured alpha-chloro centre define this member of the chloropropionate family. The alcohol-derived fragment is 2-methylpropyl, while the chlorine-bearing stereocentre lies next to the ester carbonyl. CAS 83261-15-8 therefore specifies both the ester group and the required configuration. In optically active chloropropionate chemistry, the receiving route determines the choice of alkoxy group as well as the acceptable S/R composition. Qualification should combine identification of the branched ester, a quantitative chemical assay and a method that resolves the R enantiomer. Review residual isobutanol, lactate precursor or other ester species according to the selected preparation and subsequent reaction.

Chemical identity

Chemical name
Isobutyl (S)-2-chloropropionate
CAS number
83261-15-8
Molecular formula
C7H13ClO2
Molecular weight
164.63 g/mol

Application context

Optically active chloropropionate synthesis includes the isobutyl (S) ester as a chiral building block for herbicide-intermediate development. Its 2-methylpropyl group and S configuration must both match the receiving route. Quantify the R enantiomer with chiral GC or another suitable stereoselective method. Review residual isobutanol, lactate precursor and other ester species when relevant to the source process, and agree the assay basis used for charging.

Chemistry and synthetic role

The C–Cl bond lies at the stereocentre adjacent to the ester carbonyl. The isobutyl fragment is attached through oxygen and introduces no additional stereocentre. Substitution chemistry at the alpha carbon and chemistry of the ester group are different reaction choices; the intended route determines which attributes need qualification.

Quality review

Identify the branched ester explicitly

Ask for structural identification that establishes the 2-methylpropyl ester. An isomeric butyl ester can share a molecular formula while representing a different feedstock.

Quantify the R enantiomer separately

Agree a chiral GC or other demonstrated stereoselective method with adequate resolution. A routine GC area percentage cannot by itself prove the specified S/R profile.

Review source-dependent volatile residues

Review residual isobutanol, lactate precursor and other ester species relevant to the proposed preparation. Agree the selected analytes, reporting basis and limits against the receiving reaction.

Preparing a specification

State CAS 83261-15-8, the isobutyl ester and the (S) configuration together. Define chemical assay, the opposite-enantiomer limit and method, and any route-relevant alcohol, lactate or alternative-ester limits. Add water or acidity criteria only when the receiving process requires them; specify whether results are reported as received or on a corrected basis.

Packaging and storage

Confirm packaging format, net weight and transport arrangements for the selected grade, order quantity and destination. Request the applicable SDS and label to establish storage and handling conditions.

Documentation

Request a batch COA with separate chemical and chiral results, the identification method and a chromatogram showing enantiomer resolution. Confirm availability of route-relevant residual-component data and the SDS for the selected grade.

Procurement questions

Is isobutyl chloropropionate the same as n-butyl chloropropionate?

No. The alkyl group has a different connectivity. Include the CAS and 2-methylpropyl ester identity in the purchase specification.

Can ordinary GC establish the S configuration?

Only a method demonstrated to distinguish the enantiomers can determine their ratio. Identity assignment and chemical assay should accompany that test.

What should be reviewed before changing from another chloropropionate ester?

Confirm the 2-methylpropyl group, S/R requirement and compatibility of the isobutyl ester with the next transformation and work-up.

Technical sources
  1. Japanese chemical substance notification record: (S)-2-chloropropionic acid isobutyl esterMinistry of Health, Labour and Welfare, Japan
  2. Isobutyl (S)-2-Chloropropionate, product 028797Parchem
  3. EP0380393B1 — Preparation of 2-chloropropionic-acid estersEuropean Patent Office / Google Patents
  4. CN1868997A — Method of preparing optically active chloropropionatesZhejiang University of Technology / Google Patents