- PROCESS FOR PRODUCING 1,5-DIBROMONAPHTHALENE
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PROBLEM TO BE SOLVED: To provide a process for producing 1,5-dibromonaphthalene that can efficiently produce 1,5-dibromonaphthalene. SOLUTION: 1,5-dibromonaphthalene is produced by a process for producing 1,5-dibromonaphthalene having a bromination step of reacting at least one of naphthalene and 1-bromonaphthalene with bromine in the presence of a porous material. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0032-0049
(2018/03/23)
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- Selective bromination of 1-bromonaphthalene: Efficient synthesis of bromonaphthalene derivatives
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Selective and specific preparation methods are described for 1,4-dibromonaphthalene, 1,5-dibromonaphthalene and 1,3,5-tribromonaphthalene. The reaction of 1-bromonaphthalene and naphthalene with stoichometric quantities of bromine by using a minimum amount of solvent (methylene chloride) at -30 and -50°C smoothly affords 1,4-dibromonaphthalene in 90% yield. Photobromination of 1-bromonaphthalene in CCl4 at -30°C gives 1,2,3,4,5-pentabromo-1,2,3,4-tetrahydronaphthalenes, whereas 1,5-dibromonaphthalene is obtained at reflux (77°C) in 80% yield under the same conditions. Dehydrobromination of the pentabromide by t-BuOK affords 1,3,5-tribromonaphthalene as a sole product (91%). 1,5-Dibromo- and 1,3,5-tribromonaphthalenes were efficiently converted to the corresponding methoxy naphthalene derivatives.
- Cakmak, Osman,Demirtas, Ibrahim,Balaydin, Halis T
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p. 5603 - 5609
(2007/10/03)
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- Bromination of naphthalene and derivatives: High temperature bromination XI
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Thermal and photobromination of naphthalene and derivatives have been studied. Several hexabromo- (12, 13, 16 and 17), and tetrabromotetralin derivatives (23, 24, and 25) have been obtained as the major products, besides bromonaphthalene derivatives. Base-promoted elimination reactions of 12, 13, 16 and 17 provided di- (8) tri- (10) and tetrabromo-naphthalenes (22). A convenient method was developed for the synthesis of 1,3- dibromonaphthalene (26) starting from (24). The structures of these products were determined by 1H-,13C- NMR data and X-ray structural analysis.
- Dastan, Arif,Tahir, M. Nawaz,Uelkue, Dincer,Balci, Metin
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p. 12853 - 12864
(2007/10/03)
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- Bromination of Decalin and Its Derivatives. 9. High Temperature Bromination
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Thermal and photobromination of decalin, 1, was studied, trans,cis,trans-2,5,7,9-tetrabromooctalin, 2, was obtained as the major product along with smaller amounts of bromonaphthalene derivatives. The structures of the products were determined by 1H- and 13C-NMR data and single X-ray structural analysis. Bromination of the two decalin derivatives 9 and 10 results in the formation of single isomers 11 and 12, respectively. The three tetrabromides 2, 11, and 12 were shown by molecular mechanics calculations to be the most stable stereoisomer in each case. The formation of these tetrabromides under thermodynamic control is postulated.
- Dastan, Arif,Nawaz Tahir,Uelkue, Dincer,Shevlin, Philip B.,Balci, Metin
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p. 4018 - 4022
(2007/10/03)
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