DE2419223

• Main Authors: DAM, HENDRIK TJAPKO VAN, SCHOOT, CORNELIS JOHANNES, PONJEE, JOHANNES JACOBUS
• Format: Patent
• Language: English
• Published: 14.05.1980
• Edition: 3
• Subjects: ADHESIVES; ADVERTISING; CHEMISTRY; CRYPTOGRAPHY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DISPLAY; DISPLAYING; DYES; EDUCATION; FREQUENCY-CHANGING; HETEROCYCLIC COMPOUNDS; LABELS OR NAME-PLATES; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; ORGANIC CHEMISTRY; PAINTS; PHYSICS; POLISHES; SEALS; SIGNS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

1427489 Dipyridyl derivatives PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 1 May 1974 [4 May 1973] 19066/74 Heading C2C [Also in Divisions H3-H5] Compounds of the Formula A where R 1 and R 2 are ethyl or propyl, n is 4, m is 2 or 3 and X is a mono-anion such as chlorate or tetrafluoroborate, are prepared by reacting the compound B with compound C or compound D in a polar aprotic solvent between room temperature and the boiling point of the reaction mixture. Compound C is prepared from the N- alkyldipyridyl bromide and 1,4-dibromobutane, and reacts with bipyridyl to give compound B. The latter gives compound D on reaction with 1,4-dibromobutane. Suitable solvents for the above reactions are dimethylformamide, acetonitrile, sulfolane, dimethylsulphoxide and propylenecarbonate.