Synthesis 2002(2): 0221-0224
DOI: 10.1055/s-2002-19812
PAPER
© Georg Thieme Verlag Stuttgart · New York

A Simple Key for Benzylic Mono- and gem-Dibromination of Primary Aromatic Amine Derivatives Using Molecular Bromine [1]

Anirban Kar, Narshinha P. Argade*
Division of Organic Chemistry (Synthesis), National Chemical Laboratory, Pune 411 008, India
Fax: +91(20)5893153; e-Mail: argade@dalton.ncl.res.in ;
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Publikationsverlauf

Received 25 September 2001
Publikationsdatum:
03. August 2004 (online)

Abstract

Quantitative benzylic mono- and gem-dibromination on primary aromatic amine derivatives have been achieved using molecular bromine and by protecting the amino group as a succinimide moiety. The reactions of N-(o/m/p-tolyl)succinimides 5a-c with 1.25 equivalents of molecular bromine in CCl4 at room temperature furnished the corresponding benzylic monobrominated products 6a-c in 92-94% yields, while with 2.5 equivalents of molecular bromine in refluxing CCl4 gem-dibromo products 7a-c were obtained in 94-96% yields. It is also possible to carry out nuclear bromination in these N-protected primary aromatic amines at an alternate site by using suitably substituted aniline derivatives. Thus the reaction of 3 with 1.25 equivalents of molecular bromine in acetic acid gave the desired monobrominated product 4 in nearly 100% yield.

1

NCL Communication No. 6615.

1

NCL Communication No. 6615.

5

Ref.,2a see page 437.

10

Ref.,2c see page 1265.