Chromium trioxide, oxidation

Appropriate pyrido[2,3-d]pyrimidin-5-ones with formyl groups in the 6-position have been oxiized to piromidic (68) and pipemidic (69) acids, or to intermediates for these, using moist silver oxide, chromium trioxide (potassium dichromate), potassium permanganate or, alternatively, sodium chlorite/hydroxylamine-O-sulfonic acid. 6-Acetyl groups have been similarly oxidized using sodium hypobromite in aqueous dioxane, whilst 2-acetyl groups give dimethylaminomethylene derivatives en route to 2-pyrazolylpyrido[2,3-d]pyrimidines. [Pg.210]

Chemical Designations - Synonyms-. Chromic Acid Chromic Oxide Chromium Trioxide Chemical Formula-. C1O3. [Pg.86]

The Collins/Sarett oxidation (chromium trioxide-pyridine complex), and Corey s PCC (pyridinium chlorochromate) and PDC (pyridinium dichromate) oxidations follow a similar pathway as the Jones oxidation. All these oxidants have a chromium (VI), normally yellow, which is reduced to Cr(IV), often green. [Pg.318]

In early work, />-chloranil was used to prepare the oxazines 106-108 from the corresponding 5,6-dihydro derivatives (Equation 10) < 1962CB1460>. The reaction proceeded in a very low yield for 106 and yields of 55% for 107 and 15% for 108. Mercurous oxide, chromium trioxide, and selenium dioxide were also tried unsuccessfully as oxidants for this process. [Pg.481]

The typical Phillips catalyst comprises chemically anchored chromium species on a silica support. The formation of a surface silyl chromate, and eventually silyl dichromate [scheme (29)], is significant during the catalyst preparation, because at the calcination temperature chromium trioxide would decompose to lower-valent oxides. Chromium trioxide probably binds to the silica as the chromate initially, at least for the ordinary 1% loading. However, some rearrangement to the dichromate at high temperature may occur. It is incorrect to regard only one particular valence state of chromium as the only one capable of catalysing ethylene polymerisation. On the commercial CrOs/silica catalyst the predominant active species after reduction by ethylene or carbon monoxide [scheme (59)] is probably Cr(II), but other species, particularly Cr(III), may also polymerise ethylene under certain conditions ... [Pg.116]

SYNS ANHYDRIDE CHROMIQUE (FRENCH) ANIDRIDE CROMICA (ITALIAN) CHROME (TRIOXYDE de) (FRENCH) CHROMIC ACID CHROMIC(VI) ACID CHROMIC ACID, soKd (NA 1463) (DOT) CHROMIC ACID, solution (UN 1755) pOT) CHROMIC ANHYDRIDE CHROMIC TRIOXIDE CHROMIUxM OXIDE CHROMIUM(VI) OXIDE CHROMIUM TRIOXIDE CHROMIUM(6+) TRIOXIDE CHROMIUM TRIOXIDE, anhydrous pOT) CHROMIUM TRIOXIDE, anhydrous pN 1463) pOp CHROMO (TRIOSSIDO di) (ITALIAN) CHROMS-AEUREANHYDRID (GERMAN) CHROMTRIOXID (GERMAN) CHROOMTRIOXYDE pUTCH) CHROOMZUURANHYDRIDE pUTCH) MONO-CHROAQUM OXIDE D MONOCHROMIUM TRIOXIDE O PURATRONIC CHROMIUM TRIOXIDE... [Pg.365]

BUTANIC ACID (107-92-6) C4H,02 CH3(CH2)2C00H Combustible liquid [explosion limits in air (vol %) 2 to 10 flash point 161°F/72°C cc autoignition tenp 842°F/450°C Fire Rating 2]. Violent reaction with amines, strong oxidizers, chromium trioxide >212°F/>100 (incandescent reaction) furfuryl alcohol (explosion), hypochlorites, isocyanides, nitromethane, chromic acid, nitric acid, hydrogen peroxide, phosphorus pentaoxide, all bases (exothermic reaction) reducing... [Pg.163]

HYDROXYBUTANE (78-92-2) Forms explosive mixture with air (flash point 75°F/4°C). Forms an unstable peroxide product in air. Violent reaction with strong oxidizers, chromium trioxide. Reacts, possibly violently, with alkalineearth and alkali metals, producing flammable hydrogen gas. Incompatible with strong acids, strong caustics, aliphatic amines, isocyanates, acetaldehyde, benzoyl peroxide, chromic acid, chromium oxide, dialkylzincs, dichlorine oxide, ethylene oxide, hypochlorous acid, isopropyl chlorocarbonate, lithium... [Pg.639]

Incompatibilities and Reactivities Strong oxidizers, chromium trioxide,... [Pg.137]

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