Hydrochloric Acid → Hydrochloric Acid
Reaction equation
[Cl:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[CH:5]=[CH:4][CH:3]=1.Cl.[H][H]>>[CH:10]1[C:11]2[C:6](=[CH:5][CH:4]=[CH:3][CH:2]=2)[CH:7]=[CH:8][CH:9]=1.[ClH:1]Participants
Procedure
High conversions of 1-chloro- or 1-bromonaphthalene coupled with a long catalyst life can be achieved by the zeolites used according to the invention. The conversion of 1-chloronaphthalene over an amorphous aluminosilicate, in spite of an HCl atmosphere, dropped from 51 to 41% in the course of 4 hours (temperature 400° C., LHSV 0.2 h-1, N. N. Vorozhtsov, Jr. and A. M. Beskin, J. Gen. Chem. USSR, 24, 667/672 (1954) English edition). In contrast, an HEU-1 zeolite converted 56% of 1-chloro-naphthalene after 1 hour and 41% after 7 hours in a hydrogen atmosphere at the same temperature but 2.5 times the LHSV. The selectivity for the isomerization of 1-chloronaphthalene over HEU-1 is very high and is more than 98% at reaction temperatures of between 300° and 400° C. Naphthalene above all is formed as a by-product by elimination of HCl. Less than 0.05% of dichloronaphthalenes is formed. In the reaction of 1-bromonaphthalene, however, transbromination to naphthalene and dibromonaphthalenes occurs. The selectivity for 2-bromo-naphthalene is nevertheless very high, at 95% at 350° C. and 50% conversion.
Workup
- customafter 1 hour
- customat reaction temperatures of between 300° and 400° C
Sources & evidence
- ORD record
- ord-a8a44f2a75484bdfbf5701ec4155827d
- Source dataset
- uspto-grants-1991_08
- Patent number
- US05043493
Reaction notes
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