• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.916-920
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• 2003

Photoreactions of N-(2,4-dibromonaphthyl)arenecarboxamides in basic medium result in the intramolecular substituted products, 2-aryl-8-bromonaphthoxazoles in moderate yields and further photoreactions of the products afford the reduced products, 2-arylnaphthoxazoles. These reactions are straightforward for syntheses of naphthoxazole derivatives. Since the intramolecular photosubstitution of the bromoarenecarboxamide by the oxygen of its amide group is more effective than the photoreduction of the substituted product, 2-aryl-8- bromonaphthoxazole in basic medium, the intramolecular substituted product, 2-aryl-8-bromonaphthoxazole can be isolated. A charge-transfered excited singlet state of an imidol form of the 2-bromoarenecarboxamide is involved in the photosubstitution, whereas an excited triplet state of the 2-aryl-8-bromonaphthoxzole is closely involved in the photoreduction.

• Journal of Photoscience
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• v.7 no.4
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• pp.135-138
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• 2000

The photochemical behavior of haloarene tethered to alkyl by an amide bone(1,2) was studied. The photoreaction of N-(2-bromophenyl) cyclohexanecarboxamide (1b) in basic medium afforded intramolecular substitute product, 2-cyclohexylbenzoxazole (4) and reduced product, N-phenylcyclohexanecarboxamide (5)in 33 and 26% yield, respectively. The chloro analogue(1a) produced photo-Fries type and photosubstituted products(6,4), whereas the iodo analogue produced extensively photoreduced product 5. N-(2-bromophenyl)-N-methylcyclohexanecarboxamide (2), which can not exist as imidol form, produced a photocyclized product, supporting as imidol form is involved in the intramolecular photosubstitution. since the photoreduction but the photosubstitution reaction is retarded by the presence of oxygen, a trilpet state for the photoreduction and a singlet state for the photosubstitution are involved.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1208-1254
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• 2002

Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl) acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed.

• Proceedings of the Korean Society of Potoscience Conference
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• 2002.06a
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• pp.89-89
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• 2002

• Journal of Photoscience
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• v.7 no.1
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• pp.5-8
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• 2000

Irradiation of 2'-bromobenzanilide in acetonitrile containing sodium hydroxide under nitrogen leads to the formation of the intramolecular photosubstituted product, 2-phenylbenzoxazole (45 %) along the minor photoreduced and photo-Fries type product. The photoreaction of 2'chlorobenzanilide under the same condition as above gives the photo-Fries type reaction product, 2-amino-3-chlorobenzophenone (22%) with minor product, 2-phenylbenzoxazole. The photoreaction of 2'-chlorobenzanilide in acetonitrile produces a photocyclized product, phenanthridone (19%) along with minor products, 2-phenylbenzoxazole, benzanilide, 2-amino-3-chlorobenzophenone, and 4-amino-3-chlorobenzophenone, while that of 2'-bromobenzanilide produces photosubstituted product, 2- phenylbenzoxazole.