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HONGKUN / PRODUCT DIRECTORY

Chloromethyl ethyl ether | CAS 3188-13-4

An ethoxymethylating reagent used in hydroxyl-group protection, providing the EOM unit through a chloromethyl ether structure whose identity and water exposure deserve specific attention during qualification.

CAS3188-13-4
Molecular formulaC3H7ClO
Molecular weight94.54 g/mol

Product overview

Chloromethyl ethyl ether carries the ethoxymethyl unit used in EOM protection chemistry. Its formula, C3H7ClO, describes a chloromethyl group attached to ethoxy oxygen; the chlorine is not at the end of a two-carbon chloroethyl chain. The distinction matters when selecting a protecting reagent from similarly named ethers. In multistep synthesis, temporary modification of a hydroxyl group allows a route to address other functional groups before deprotection. Reagent assay, water exposure and the composition of the selected grade should be reviewed together when calculating a charge.

Chemical identity

Chemical name
Chloromethyl ethyl ether
CAS number
3188-13-4
Molecular formula
C3H7ClO
Molecular weight
94.54 g/mol

Application context

Alkoxymethyl protection is used to manage hydroxyl functionality during organic synthesis. Chloromethyl ethyl ether provides an ethoxymethyl group, giving an EOM ether rather than the methoxymethyl derivative obtained with a MOM reagent. Choosing this protection strategy depends on the substrate and the subsequent transformations, including the conditions planned for removal of the protecting group. For purchasing, specify the EOM reagent explicitly and assess its suitability against the actual route. Analytical evidence should address intact reagent rather than chloride content alone, since chloride measurement cannot establish the organic connectivity or active reagent concentration.

Chemistry and synthetic role

The electrophilic chloromethyl site and ethoxy group form the EOM donor. Its connectivity is ClCH2–O–CH2CH3, distinct from 2-chloroethyl ethers.

Quality review

Verify the ether connectivity

Use an identity method capable of distinguishing chloromethyl ethyl ether from chloroethyl ethers.

Measure intact reagent

Agree an organic assay method and basis for calculating reagent quantity.

Control water exposure

Set water criteria and container-handling requirements suitable for the selected reagent and route.

Preparing a specification

Specify chloromethyl ethyl ether by CAS, EOM identity, assay method and concentration or neat form. Agree water and route-relevant degradation limits.

Packaging and storage

Packaging and net weight are agreed for the selected grade, order quantity and destination. Check the actual supplier SDS and label for storage and transport requirements.

Documentation

Request a batch COA, SDS and the analytical methods for the acceptance criteria below. Confirm which supporting chromatograms and identity data are available from the selected manufacturer.

Procurement questions

Is this a 2-chloroethyl ether?

No. Chlorine is attached to the carbon directly next to the ether oxygen.

Can chloride analysis establish reagent assay?

It does not by itself distinguish intact reagent from other chloride-containing species.

Why include water in the purchase brief?

Moisture can affect chloromethyl-ether integrity and the effective reagent charge.

Technical sources
  1. PubChem CID 18523NCBI / PubChem
  2. Chloromethyl ethyl etherTCI
  3. Alkoxymethylation protecting agentsTCI