2605-69-8Relevant academic research and scientific papers
Reactions of dimethoxycarbene with cyclic perchlorinated olefins and ketones
Dunn, James A.,Pezacki, John Paul,McGlinchey, Michael J.,Warkentin, John
, p. 4344 - 4352 (2007/10/03)
Reactions of dimethoxycarbene (2), a carbonyl group equivalent, with perchlorinated olefins and ketones were investigated. Thermolysis of 2,2- dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline (1) at 110 °C generated 2, which reacted with hexachlorocyclopentadiene (4), octachlorocycloheptatriene (12), octachlorobicyclo[3.2.0]hepta-3,6-diene (24), hexachlorotropone (28), hexachlorobicyclo[3. 2.0]-hepta-3,6-dien-2-one (32), and tetrachloro-1,4- benzoquinone (35). Reactions of 2 with perchlorinated olefins 4, 12, and 24 led to esters or, in the case of 12, to a ketene acetal. Their formation is rationalized in terms of Michael-like addition and displacement (S(N)2' or S(N)2', if concerted) of allylic chlorine atoms by 2, yielding ion pairs that either dechloromethylate to esters or dechlorinate to a ketene acetal. In contrast, the reactions of 2 with unsaturated perchloroketones 28, 32, and 35 led to ring contraction, ring expansion, and aromatization, respectively. The products from these reactions are consistent with nucleophilic addition of 2 at the carbonyl moiety rather than Michael-type addition. Dimethoxycarbene- d3 was used to show that demethylation in the latter reaction was intermolecular. Mechanisms for the different reaction courses are proposed.
A New Trifluoromethylating Agent: Synthesis of Polychlorinated (Trifluoromethyl)benzenes and 1,3-Bis(trifluoromethyl)benzenes and Conversion into Their Trichloromethyl Counterparts and Molecular Structure of Highly Strained Polychloro-m-xylenes
Castaner, J.,Riera, J.,Carilla, J.,Robert, A.,Molins, E.,Miravitlles, C.
, p. 103 - 110 (2007/10/02)
Mixtures of CCl3F and AlCl3 replace CF3 for H in polychlorobenzenes.Thus, by treatment of a solution of the suitable polychlorobenzene in CCl3F with AlCl3, the following compounds can be prepared: pentachloro- (2), 2,3,4,5-tetrachloro- (5), 2,3,4,6-tetrachloro- (8), 2,3,5,6-tetrachloro- (11), 2,3,4-trichloro- (14), 2,4,5-trichloro- (17), and 2,4,6-trichloro-1-(trifluoromethyl)benzene (20), as well as 4,5,6-trichloro- (31) and 2,4,6-trichloro-1,3-bis(trifluoromethyl)benzene (32).The reaction of the above-mentioned trifluoromethylated compounds with AlCl3 in CS2 yieldstheir trichloromethyl counterparts: 3, 6, 9, 12, 15, 18, 21, 34, and 36.The chlorination of 32 or 36 by means of Silberrad's reagent (SO2Cl2, AlCl3, and S2Cl2) affords perchloro-m-xylene (38), a new highly strained chlorocarbon whose synthesis was attempted repeatedly in the past. 9, 15, 17, and 21, when treated with oleum and then with water, are converted into 2,3,4,6-tetrachloro- (22), 2,3,4-trichloro- (23), 2,4,5-trichloro- (24), and 2,4,6-trichlorobenzoic acid (25), respectively; under similar treatment, 34, 36, and 38 give 4,5,6-trichloro- (33), 2,4,5-trichloro- (35), and tetrachloroisophthalic acid (39), respectively.The formation of the (trifluoromethyl)benzenes is discussed, and in this connection it has been found that CCl3F solutions of 3 and 18 in the presence of AlCl3 give back 2 and 17, respectively.Molecular structures of highly strained m-xylenes 36 and 38, as well as that of the much less strained 34, ascertained by X-ray analysis, are reported and commented.IR, UV, and NMR spectral data of the compounds synthesized are presented.The interesting UV spectrum of 21 is discussed.
NEW SYNTHESIS OF POLYCHLORO(TRIFLUOROMETHYL)BENZENES AND HIGHLY STRAINED POLYCHLORO(TRICHLOROMETHYL)BENZENES
Riera, Juan,Castaner, Juan,Carilla, Jose,Robert, Ana
, p. 3825 - 3828 (2007/10/02)
Several polychloro(trifluoromethyl)benzenes have been prepared by treatment of the corresponding polychlorobenzenes with CCl3F and AlCl3.The resulting trifluoromethyl derivatives, by reaction with the same inorganic halide in CS2, give their trichloromethyl analogues.
DESTRUCTIVE CHLORINATION OF ALKYLBENZENES ON HETEROGENEOUS CATALYSTS.
Potapov,Valitov,Evdokimova
, p. 321 - 324 (2007/10/02)
A study was made of the destructive chlorination of alkylbenzenes in the vapor phase on metal oxides and metal chlorides. This work shows that 380-400 degree C, 11-12 sec contact time, 0. 3-0. 8 mass % MoO//3 on alumina, 7-10% stoichiometric excess of chlorine, and 1:9 toluene/chlorine mole ratio were optimal for the chlorination of toluene to give C//6Cl//6 and CCl//4. The optimal conditions for the preparation of pentachlorobenzyl chloride were 295-320 degree C, 18-22 sec contact time, 1:6 toluene/chlorine mole ratio, and 4-8. 5 mass % MgCl//2 on KSK silica gel. The optimal yields of CCl//4 and C//6Cl//6 were 97. 4-98. 2 and 93. 8-96. 3 mole %, respectively, with 91-93 mole % conversion of chlorine.
