Haloalkyl-3-imidazoline-3-oxides with Nucleophilic Reagents

Interaction of 4-Haloalkyl-3-imidazoline-3-oxides with Nucleophilic Reagents 

Numerous derivatives of imidazoline nitroxides with various functional groups have been obtained in the investigations of reactions of 4-alkyl-halide- and 4-alkyl-dihalide-3-imidazoline-3-oxides. The interaction of compounds 7a,b with an equimolar quantity of iV-bromo- and N-chloro-succinimide leads to 4-bromomethyl-, 4-a-bromoethyl-, and 4-a-chloro-ethyl-3-imidazoline-3 oxides (64a,b) (Kutikova and Volodarsky, 1973 Grigor ev and Volodarsky, 1975). With the addition of excess iV-succinimide halide 4-dibromomethyl-, 4-dichloromethyl-, and 4-a,a-dichloroethyl-3-imidazoline-3-oxides (65a,b) are formed (Grigor ev and Volodarsky, 1974 Grigor ev et a/., 1975 Mitasov et ai, 1978). Nitroxides 64 and 65 are reduced by zinc to diamagnetic 1-hydroxy-derivatives 66 and 67. 

In the interaction of 4-a-bromoethyl-3-imidazoline-3-oxide (64b, X = Br) with primary amines, nucleophilic substitution products 70b were isolated, which upon heating are quantitatively converted to imines 68b. 

The reaction of both bromomethyl derivative 64a and a-bromoethyl derivative 64b with secondary amines leads to nucleophilic substitution products that form aldehyde and ketone 71a,b when allowed to remain in solution. This occurs via the intramolecular oxidation of the amino group by the nitrone-group oxygen. Aldehyde and ketone 71a,b are also formed in the acid hydrolysis of imines 68a,b (Grigor ev and Volodarsky, 1975). 

The interaction of bromo derivatives 64a,b with excess hydroxylamine results in the formation of oximes with preservation of iV-oxide grouping 43a, in addition to the reduction of the radical center. The interaction of 64a,b with other nucleophiles (KI, KSCN, KN3, AcOK, phthalimide K, and sodium malonic ester) gives corresponding nucleophilic substitution 

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