Cyclobutanone

Structural formula
General
Surname	Cyclobutanone
Molecular formula	C 4 H 6 O
Brief description	colorless liquid
External identifiers / databases
CAS number 1191-95-3 EC number 214-745-6 ECHA InfoCard 100.013.405 PubChem 14496 Wikidata Q1147434
properties
Molar mass	70.09 g mol −1
Physical state	liquid
density	0.9547 g cm −3 (0 ° C)
Melting point	−50.9 ° C
boiling point	99.75 ° C
solubility	soluble in water, diethyl ether, benzene, chloroform and toluene
Refractive index	1.4215 (20 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 226 P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Cyclobutanone is a four-ring ketone and the second member of the homologous series of cyclic ketones ( cycloalkanones ). In contrast to cyclopropanone , the smallest but extremely unstable cyclic ketone, cyclobutanone is a liquid that can be stored and is stable at room temperature and can be distilled.

History and representation

The Russian chemist Nikolai Kischner first reported on this substance in 1905. He obtained cyclobutanone in low yield from cyclobutanecarboxylic acid in several reaction steps. The synthesis process is cumbersome and ineffective by today's standards.

As a result, more productive syntheses were worked out. The older processes involve degradation reactions of C _{5 building} blocks. For example, the oxidative decarboxylation of cyclobutanecarboxylic acid has been improved using other reagents and methods. A new, anabolic route to cyclobutanone was found by P. Lipp and R. Köster, who made a solution of diazomethane in diethyl ether react with ketene . This reaction is based on a ring expansion of the primarily formed cyclopropanone, whereby molecular nitrogen is split off. The reaction should be carried out with caution, however, since diazomethane is explosive; the gaseous ketene has to be produced in a special apparatus. The reaction mechanism could be confirmed by a reaction using ¹⁴ C-labeled diazomethane.

The “best method” for the synthesis of cyclobutanone is said to be the lithium iodide-catalyzed rearrangement of oxaspiropentane , which is formed from the easily accessible methylenecyclopropane by epoxidation :

Seebach's dithiane method and the solvolytic cyclization of butynyl triflate are recommended in Organic Synthesis as further synthetic approaches to the four-ring ketone. While Seebach's synthesis is constructive (C ₃ + C _{1 building} blocks), the other two processes represent conversions of C _{4 building} blocks.

properties

Physical Properties

Cyclobutanone is a colorless liquid at room temperature. The boiling point under normal pressure is 99.75 ° C. The corresponding heat of vaporization is 38.2 kJ mol ⁻¹ . According to Antoine, the vapor pressure function results from log ₁₀ (P) = A− (B / (T + C)) (P in bar, T in K) with A = 5.00324, B = 1740.994 and C = −19.419 in the temperature range from 249.1 to 298.4 K.

Chemical properties

Steam of cyclobutanone (C ₄ H ₆ O) heated to approx. 350 ° C breaks down into ethene (C ₂ H ₄ ) and ketene (H ₂ C ₂ O). The activation energy for this [2 + 2] cycloreversion is 217.7  kJ / mol . The formally simple retro reaction, i.e. H. the [2 + 2] cyclo addition of ketene to ethene has never been observed. Apparently it is much slower than the dimerization of ketene to diketene.

use

Cyclobutanone can be used in organic synthesis in the laboratory as a starting material for the production of other cyclobutane derivatives. It probably has no meaning in industrial chemistry.

Individual evidence

1. ↑ ^{a b c d e} David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-124.
2. ↑ ^{a b c} G. Wolf: Thermochemical investigations on cyclic ketones , in: Helv. Chim. Acta 55 (1972) pp. 1446-1459; doi : 10.1002 / hlca.19720550510 .
3. ↑ ^{a b} Datasheet Cyclobutanone, 99% from Sigma-Aldrich , accessed on August 4, 2011 ( PDF ).
4. ↑ N. Kishner: About the Cyklobutanon , Journal der Russischen Physikalisch-Chemischen Gesellschaft , 37 , pp. 106-109 (1905); On the action of bromine on the amides of α-bromo-substituted acids , ibid. 37, pp. 103-105 (1905), cited in Chemisches Zentralblatt , 1905 I, 1220 or 1219.
5. ↑ Dieter Seebach : Isocyclic four-ring compounds in Houben-Weyl -Müller, Methods of Organic Chemistry, Volume IV / 4, Georg Thieme Verlag, Stuttgart 1971.
6. ^ P. Lipp and R. Köster, Reports of the German Chemical Society , 64, pp. 2823-2825 (1931).
7. ↑ S. Kaarsemaker, J. coops, Recueil des Travaux Chimiques des Pays-Bas , 70, p 1033 (1951).
8. ↑ DA Semenow, EF Cox, JD Roberts: Small-Ring Compounds. XIV. Radioactive Cyclobutanone from Ketene and Diazomethane- ¹⁴ C , in: J. Am. Chem. Soc. , 78 (1956) pp. 3221-3223, doi : 10.1021 / ja01594a069 .
9. ↑ JR Salaün, JM Conia: Oxaspiropentane. A Rapid Route to Cyclobutanone , Journal of the Chemical Society D: Chemical Communications , 1971, pp. 1579b-1580; doi : 10.1039 / C2971001579B .
10. ↑ ^{a b} J. R. Salaün, J. Champion, JM Conia: Cyclobutanone from Methylenecyclopropane via Oxaspiropentane In: Organic Syntheses . 57, 1977, p. 36, doi : 10.15227 / orgsyn.057.0036 ; Coll. Vol. 6, 1988, p. 320 ( PDF ).
11. ↑ D. Seebach, AK Beck: Cyclic Ketones from 1,3-Dithiane: Cyclobutanone In: Organic Syntheses . 51, 1971, p. 76, doi : 10.15227 / orgsyn.051.0076 ; Coll. Vol. 6, 1988, p. 316 ( PDF ).
12. ↑ ^{a b} M. Hanack, T. Dehesch, K. Humm, A. Nierth: Cyclobutanone In: Organic Syntheses . 54, 1974, p. 84, doi : 10.15227 / orgsyn.054.0084 ; Coll. Vol. 6, 1988, p. 324 ( PDF ).
13. ^ KB Wiberg, KM Morgan, H. Maltz: Thermochemistry of carbonyl reactions. 6. A study of hydration equilibria , in: J. Am. Chem. Soc. , 116 (1994) pp. 11067-11077; doi : 10.1021 / ja00103a024 .
14. ^ SW Benson, GB Kistiakowsky: The Photochemical Decomposition of Cyclic Ketones , in: J. Am. Chem. Soc. , 64 (1942) pp. 80-86; doi : 10.1021 / ja01253a021 .
15. ^ MN Das, F. Kern, TD Coyle and WD Walters: The Thermal Decomposition of Cyclobutanone , in: J. Am. Chem. Soc. , 76, pp. 6271-6274 (1954); doi : 10.1021 / ja01653a013 .