Ketene lamp

The production of ketene by this method has no significant environmental impact. The off-gases from the ketene furnace are either circulated to the furnace and burned to save energy or led to a flare system. The reaction can also be carried out at 350—550°C in the presence of alkaH-exchanged zeoHte catalysts (54). Small quantities of ketene are prepared by pyrolysis of acetone [67-64-1] at 500—700°C in a commercially available ketene lamp (55,56). 

Ketene diethylacetal, 23, 43 Ketene, diethyl ketal, 23, 43 Ketene dimer, 21, 4, 64 Ketene lamp, 21, 65 Keto acid, 20, 2... 

Ketene can be prepared conveniently and in good yield by means of E. Ott s ketene lamp h1... 

Ketene can be generated conveniently by pyrolysis of acetone in a hot tube or over a hot wire in a ketene lamp, or by pyrolysis of diketene in a hot tube. Other methods of preparation have been summarized. It has been shown that diketene cracks quite cleanly to ketene, although some allene and carbon dioxide are formed at the same time. ... 

Ketene may be generated conveniently from acetone by means of a ketene lamp. 1 This apparatus was used by submitters and checkers. Other apparatus (Org. Syn. Coll. Vol. 1, 324) might also be used. 

Examples for the treatment of other ketenes are few. The ordinary ketene lamp has been modified for the depolymerization of dimethylketene dimer (86%). Ethylcarbethoxyketene can be obtained from its dimer in 80-90% yields by heating at 180-200° under a pressure of 15 mm. ... 

Kerosene, purified, 24, 7 Ketene, 21, 13, 64 Ketene diethylacetal, 23, 45 Ketene, diethyl ketal, 23, 45 Ketene dimer, 21, 4, 64 Ketene lamp, 21, 65 Keto acid, 20, 2 -Ketoglutaric acid, 26, 42 Ketone, 2-Fluorenyl methyl, 28,3,63 Ketone, methyl 9-phenanthryl, 28,6 Ketone, methyl 2-thienyl, 28,1 Knoevenagel condensation, 23, 60 24, 92 25, 42, 51 27, 24 28, 24 Kolbc synthesis of an alkyl a,a>-dicar-boxylatc, 21, 48... 

Figure 5. Apparatus for preparation of Figure 6. Detail of the ketene lamp...

Dimethylketene.u A modification of the ordinary ketene lamp is necessary to permit the pyrolysis of the comparatively high-melting di-methylketene dimer (m.p. 115°), which tends to sublime out of the reaction zone. The apparatus illustrated in Fig. 2 has a triple filament made... 

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