50-43-1Relevant academic research and scientific papers
Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
Matic, Mirela,Denegri, Bernard,Kronja, Olga
supporting information, p. 8986 - 8998,13 (2012/12/12)
Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
Correlation of the rates of solvolysis of 3,4,5-trimethoxy- and 2,4,6-trichlorobenzoyl chlorides
Park, Kyoung-Ho,Kevill, Dennis N.
, p. 647 - 653,7 (2020/07/30)
The introduction of methoxy groups into the 3- and 5-positions of 4-methoxybenzoyl chloride leads to a reduction in specific rates of solvolysis. An extended Grunwald-Winstein equation correlation for the specific rates of solvolysis of 3,4,5-trimethoxybenzoyl chloride gives sensitivities towards changes in solvent nucleophilicity (l value) of 0.29 and towards changes in solvent ionising power (m value) of 0.54. The low m value allows specific rates to be determined in highly ionising fluoroalcohol-H2O mixtures. A parallel correlation of the specific rates of solvolysis of 2,4,6- trichlorobenzoyl chloride reveals that solvolyses in 100% and 90% ethanol or methanol do not appreciably follow the ionisation pathway indicated for solvolyses in the other solvents and it is proposed that, despite the two ortho-substituents, the addition-elimination pathway has become dominant.
INHIBITORS OF STEAROYL-COA DESATURASE
-
, (2009/06/27)
Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of diseases such as, for example, obesity.
Investigation of the Yamaguchi esterification mechanism. Synthesis of a Lux-S enzyme inhibitor using an improved esterification method
Dhimitruka, Ilirian,SantaLucia Jr., John
, p. 47 - 50 (2007/10/03)
(Chemical Equation Presented) A one-pot procedure for the regioselective synthesis of aliphatic esters is described. This was a result of a study on mixed aliphatic-aromatic anhydrides. The data suggest that during the Yamaguchi esterification reaction, a symmetric aliphatic anhydride is produced in situ, which upon reaction with an alcohol yields the ester. We confirmed that benzoyl chloride could be used instead of the sterically hindered Yamaguchi acid chloride. This method was successfully applied in the synthesis of Lux-S aspartic acid inhibitor.
Extensive halogen scrambling and buttressing effects encountered upon treatment of oligobromoarenes with bases
Mongin, Florence,Marzi, Elena,Schlosser, Manfred
, p. 2771 - 2777 (2007/10/03)
As a rule, tri-, tetra- and pentahaloarenes readily undergo ortho-lithiation when treated with amide-type bases. However, halogen migration occurs whenever the substrate contains three or more contiguous halogen atoms, provided that at least one of them is bromine or iodine. Dismutation and reduction processes often take place concomitantly. In this manner, a variety of organometallic intermediates may be formed, the driving force always being a decrease in basicity. When no such energy gain can be achieved, a sterically crowded substrate may just turn out to be inert; this was found to be the case with 1,5-dibromo-3-fluoro-2-(trimethylsilyl)benzene, 1,5-dibromo-3-fluoro-2,4-bis(trimethylsilyl)benzene, and 1,5-dibromo-3-fluoro-2,4-diiodobenzene. Buttressing effects are apparently strong enough to prevent expedient deprotonation of those substrates.
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.
Benzylated 1,2,3-triazoles as anticoccidiostats
Bochis,Chabala,Harris,Peterson,Barash,Beattie,Brown,Graham,Waksmunski,Tischler,Joshua,Smith,Colwell,Wyvratt Jr.,Fisher,Tamas,Nicolich,Schleim,Wilks
, p. 2843 - 2852 (2007/10/02)
Substituted 5-amino-4-carbamoyl-1,2,3-triazoles 3a-w were prepared by two synthetic schemes and evaluated in vivo for anticoccidial activity. Both schemes proceeded by brominating appropriately substituted toluenes 4a-s,v to 5a-s,v. In Scheme I, the brominated benzyl analogues 5 were converted to the corresponding benzyl azides 6, which were treated with cyanoacetamide to yield 1-substituted-5-amino-4-carbamoyl-1,2,3-triazoles 3. In Scheme II, the benzyl halides 5 were employed to alkylate the sodium salt of 5-amino-4-carbamoyl-1,2,3-triazole (7). Preliminary screening data against Eimeria acervulina and E. tenella in chickens suggested structural requirements for maximizing activity. Further evaluation against a relatively resistant series of eight Eimeria field isolates revealed L-651,582 (3a) to be a highly effective coccidiostat. However, unacceptable tissue residues precluded further development. Mechanistic studies on this series of 5-amino-4-carbamoyl-1,2,3-triazoles and, in particular, on L-651,582 (3a) revealed that its mode of action does not involve inhibition of IMP dehydrogenase, but probably interferes with host cell calcium entry. In addition, L-651,582 has been found to have antiproliferative activity in several disease models and was recently reported to possess antimetastatic activity in a model of ovarian cancer progression.
