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Expired
Application number
GB829330A
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Imperial Chemical Industries Ltd
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Imperial Chemical Industries Ltd
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Application filed by Imperial Chemical Industries LtdfiledCriticalImperial Chemical Industries Ltd
Priority to GB829330ApriorityCriticalpatent/GB357165A/en
Publication of GB357165ApublicationCriticalpatent/GB357165A/en
Organic Low-Molecular-Weight Compounds And Preparation Thereof
(AREA)
Abstract
Phthalic anhydride derivatives are obtained by replacing the nitro groups in nitrophthalic anhydrides or their derivatives by halogen, by treatment of such derivatives with halogens. Further halogenation may also occur in such process. The reaction can conveniently be carried out at a temperature at which the starting material is molten, say at 240 DEG C. In examples 3-nitrophthalic anhydride is converted to 3-chlorphthalic anhydride, a mixture of 3- and 4-nitrophthalic anhydrides to 3- and 4-chlorphthalic anhydrides (which may be separated in the form of their acids), and mononitro-4,5-dichlorphthalic anhydride (obtained by the nitration of 4,5-dichlorphthalic anhydride in nitric acid with addition of sulphuric acid) to a trichlorphthalic anhydride.
GB829330A1930-03-141930-03-14Improvements in and relating to the production of phthalic anhydride derivatives
ExpiredGB357165A
(en)