Bromine → 5-Bromoindoline

HRID 355093

Reaction equation

HRID 355093 reaction equation
C([N:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[CH2:6][CH2:5]1)(=O)C.[Br:13]Br>C(O)(=O)C>[Br:13][C:9]1[CH:8]=[C:7]2[C:12](=[CH:11][CH:10]=1)[NH:4][CH2:5][CH2:6]2

Participants

4

Reactant 2

HCID 24408BromineHCID 276731-(2,3-Dihydro-1H-indol-1-yl)ethan-1-one

Product 1

HCID 34115665-BromoindolineYield 85%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Gall et al. [J. Org. Chem., Vol. 20 (1955), p. 1538] describes the direct bromination of 1-acetyl-indoline in glacial acetic acid with bromine followed by saponification to obtain 5-bromo-indoline in 85% yield but attempts to repeat the process with chlorine results in only about a 45% yield of 5-chloro-1-acetyl-indoline. The latter result is not surprising in view of references such as Thesing et al. [Chem. Ber., Vol. 95 (1962), p. 2205], German Pat. No. 1,123,668, British Pat. No. 919,864 and the Chemistry of Heterocyclic Compounds, Vol. 25, Indoles, part II, Wiley Interscience, New York, London, Sidney, Toronto, 1972 p. 129 which teach that the reaction of N-acetylated-indoline-2-sulfonates in glacical acetic acid with chlorine, hypochlorous acid or alkali metal hypochlorites results in a variety of chlorinated products including 5- and 7-chloro compounds. Japanese Patent Application Ser. No. P 69-27967 (1969) teaches that these difficulties may be avoided by reacting 1-acetyl-indoline with N-chlorosuccinimide in carbon tetrachloride.

Sources & evidence

ORD record
ord-48cef17359854ab18669cb541b5843e6
Source dataset
uspto-grants-1983_03
Patent number
US04377699

Linked notes

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