[53970-36-8]  · C5H10BrClO  · 1-Bromomethoxy-4-chlorobutane  · (MW 201.49)

(bromomethylating agent)

Physical Data: bp 94 °C/5 mmHg.

Preparative Method: can be prepared by treating 4-chloro-1-butanol with Paraformaldehyde and dry Hydrogen Bromide.1 Subsequent aqueous workup, separation, and distillation provides the desired product in 49% yield.

Handling, Storage, and Precautions: is much less volatile and therefore more convenient and safer compared to traditional halomethylating agents such as Chloromethyl Methyl Ether, but it is still a potential carcinogenic compound. Thus, caution should be exercised while handling this compound. Use in a fume hood.

1-Bromomethoxy-4-chlorobutane is primarily used as a bromomethylating agent.1 It is a safer halomethylating reagent compared to the traditionally used agents such as chloromethyl methyl ether, which is highly volatile. 1-Bromomethoxy-4-chlorobutane reacts readily with arenes under Zinc Chloride or Titanium(IV) Chloride catalysis to produce bromomethylated arenes in good yields with THF as the byproduct, the formation of which facilitates the reaction (eq 1).

1-Bromomethoxy-4-chlorobutane can also serve as a precursor to the d-chlorobutyl carboxonium ion, which can be further utilized for the alkylation of tetrahydrofuran and tetrahydrothiophene (eq 2).2

Related Reagents.

Bromomethyl Methyl Ether; Chloromethyl Methyl Ether.

1. Olah, G. A.; Beal, D. A.; Yu, S. H.; Olah, J. A. S 1974, 560.
2. Olah, G. A.; Yu, S.; Liang, G.; Matseescu, G. D.; Bruce, M. R.; Donovan, D. J.; Arvanaghi, M. JOC 1981, 46, 571.

Geroge A. Olah, G. K. Surya Prakash, Qi Wang & Xing-ya Li

University of Southern California, Los Angeles, CA, USA

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