- Preparation method for trifluoroacetylacetone
-
The invention discloses a preparation method for trifluoroacetylacetone by a two-stage method. Firstly, a trifluoroacetate is reacted with acetone to obtain a enol sodium salt under the effect of sodium methylate and/or sodium ethylate; and secondly, the enol sodium salt is subjected to acidification, and then reduced pressure distillation is carried out, so that the trifluoroacetylacetone is obtained. The preparation method disclosed in the invention has the characteristics that the product yield is high, the method is safe and friendly to environment, the process is simple and the like.
- -
-
Paragraph 0026-0027; 0036
(2017/11/16)
-
- 1,5-Diketones Synthesis via Three-Component Cascade Reaction
-
A mild and efficient cascade synthesis of 1,5-diketones from readily available N,N-dicyclohexylmethylamine, 1,3-dicarbonyl compounds, and trifluoromethyl β-diketones has been developed. This cascade reaction occurs via an oxidation/Mannich reaction/Cope elimination/Michael addition/retro-Claisen reaction sequence, and provides multiple C-C bond formations in one pot. In addition, exquisite chemoselectivity is achieved in the reaction between 1,3-dicarbonyl compounds and trifluoromethyl β-diketones.
- Xing, Li-Juan,Lu, Tao,Fu, Wei-Li,Lou, Mei-Mei,Chen, Bo,Wang, Zhi-Shen,Jin, Yang,Li, Dan,Wang, Bin
-
supporting information
p. 3076 - 3080
(2015/11/03)
-
- Comparative study of the regioselectivity and reaction media for the synthesis of 1-tert-butyl-3(5)-trifluoromethyl-1H-pyrazoles
-
A study is presented for the synthesis of a series of 1-tert-butyl-3(5)- (trifluoromethyl)-1H-pyrazoles from the reaction of 4-alkoxy-1,1,1-trifluoro-3- alken-2-ones [CF3C(O)CH=C(R1)(OR), where R = Et and R 1 = H or R = Me and R1 = Me, Ph, 4-Me-C6H 4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-I-C 6H4, fur-2-yl, thien-2-yl, or naphth-2-yl] with tert-butylhydrazine hydrochloride. When [BMIM][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) and pyridine were used as the reaction media, we obtained a mixture of 1-tert-butyl-3(5)- trifluoromethylpyrazoles. The formation of 5-trifluoromethyl-1-tert-butyl-1H- pyrazoles with high regioselectivity occurred when the reaction was carried out with NaOH in EtOH. The formation of 1-tert-butyl-3-trifluoromethyl-1H-pyrazoles occurred, after hydrolysis of the 4-alkoxy-1,1,1-trifluoro-3-alken-2-ones in H2O and H2SO4, followed by cyclization in [BMIM][BF4] and pyridine.
- Martins, Marcos A. P.,Marzari, Mara R. B.,Frizzo, Clarissa P.,Zanatta, Marcileia,Buriol, Lilian,Andrade, Valquiria P.,Zanatta, Nilo,Bonacorso, Helio G.
-
p. 7112 - 7119
(2013/02/21)
-
- Synthesis and characterization of the titanium complexes bearing two regioisomeric trifluoromethyl-containing enaminoketonato ligands and their behavior in ethylene polymerization
-
A series of new titanium complexes bearing two regioisomeric trifluoromethyl-containing enaminoketonato ligands (3a-h and 6a-h), [PhNCRCHC(CF3)O]2TiCl2 (3a, R = Me; 3b, R = n-C5H11; 3c, R = i-Pr; 3d, R = Cy; 3e, R = t-Bu; 3f, R = CHCHPh; 3g, R = Et; 3h, R = n-C11H23) and [PhNC(CF 3)CHC(R)O]2TiCl2 (6a, R = Ph; 6b, R = n-C 5H11; 6c, R = i-Pr; 6d, R = Cy; 6e, R = t-Bu; 6f, R = CHCHPh; 6g, R = CHPh2; 6h, R = CF3) have been synthesized and characterized. X-ray crystal structures analyses suggest that complexes 3c-e and 6c-d all adopt a distorted octahedral geometry around the titanium center. Complexes 3c, 3d and 6c display a cis-configuration of the two chlorine atoms around the titanium center, while complex 6d shows a trans-configuration of the two chlorine atoms. Especially, the configurational isomers (cis and trans) of complex 3e were identified both in solution and in the solid state by NMR and X-ray analyses. With modified methylaluminoxane as a cocatalyst, all the complexes are active towards ethylene polymerization, and produce high molecular weight polymers. With the variation of the relative position of the imino group and the trifluoromethyl group of the β-enaminoketonato ligands, the polymerization behavior of the catalysts changed remarkably. It is observed that the substituent directly joined to the carbonyl in the ligands plays an important role for both the catalytic activities and the properties of the polymers produced. The Royal Society of Chemistry 2009.
- Ye, Wei-Ping,Mu, Hong-Liang,Shi, Xin-Cui,Cheng, Yan-Xiang,Li, Yue-Sheng
-
scheme or table
p. 9452 - 9465
(2010/03/04)
-
- N-benzenesulfonyl-L-proline derivatives, method for preparing and therapeutic use
-
PCT No. PCT/FR97/02049 Sec. 371 Date May 6, 1999 Sec. 102(e) Date May 6, 1999 PCT Filed Nov. 14, 1997 PCT Pub. No. WO98/24783 PCT Pub. Date Jun. 11, 1998The present invention relates to compounds selected from the group consisting of (i) the compounds of formula I: in which: X is a halogen atom or a methyl group, A is a group -N(R3)CO- or -CO-N(R3)-, B is a single bond, -CH2- or -CH2-O-, R1 is H, a C1-C3 alkyl group or a CF3 group, R2 and R3 are each independently H or a C1-C3 alkyl group, W is CH or N, and n is 2, 3, 4 or 5; and (ii) their addition salts. It further relates to the process for their preparation and to their use in therapeutics, especially for combating pathological conditions involving bradykinin.
- -
-
-
- Para-hydroxyalkylation of hydroxylated aromatic compounds
-
Hydroxylated aromatic compounds devoid of substituents in the para-position to the hydroxyl group thereof are para-hydroxyalkylated, e.g., into optionally substituted p-hydroxymandelic acid compounds, more particularly p-hydroxymandelic acid and 3-methoxy-p-hydroxymandelic acid, by condensing same with an organic carbonyl compound in the presence of a quaternary ammonium hydroxide.
- -
-
-
- The Reactions of Zinc(II) with 1,3-Diketones in Aqueous Solution. Catalysis by Cacodylic Acid during Complex Formation
-
The reactions of zinc(II) with three 1,3-diketones have been investigated in aqueous solution at 25 deg C and an ionic strength of 0.5 mol dm-3 NaClO4.The catalytic effect of cacodylic acid on the reactions of zinc(II) with pentane-2,4-dione has been demonstrated.In addition, the effect of cacodylic acid on the hydrolysis of the nickel(II) and copper(II) triglycine complexes has been investigated.
- Hynes, Michael J.,Mooney, Marie T.,Moloney, Ann
-
p. 313 - 318
(2007/10/02)
-
- HYDROLYSIS OF FLUOROALKYL-CONTAINING β-AMINOVINYL KETONES
-
The kinetics of hydrolysis of fluoroalkyl-containing β-aminovinyl ketones R1C(O)CHC(NHR3)R2, in which the substituents CF3 and HCF2CF2 are in the ketone (R1) or enamine parts of the molecule (R2), was studied.In acid (pH 10) media, they hydrolyze with the formation of the corresponding amines and β-diketones.In an alkaline medium, the β-diketones undergo cleavage to fluorinated acids and methyl ketones.The rate constants of hydrolysis in an acid medium change within a range of four orders, depensdng on the nature of the substituents.The presence of a fluoroalkyl group at the enamine reaction center increases the hydrolysis rate.In an alkaline medium, the rate constants vary within one order.
- Bazhenova, L. N.,Filyakova, V. I.,Kirichenko, V. E.,Pashkevich, K. I.
-
p. 581 - 585
(2007/10/02)
-
- Kinetics of the substitution of β-Diketones in β-diketonato(1,5-cyclooctadiene)rhodium(I) complexes by benzoyl-1,1,1-trifluoroacetone
-
The kinetics and mechanism of the reactions between and trifluorobenzoylacetone (TFBA) to give have been studied in a petroleum-ether medium at various temperatures with UV spectroscopy.The rate law is -d/dt=(ks+ky) and the reaction is shown to proceed via an associative mechanism.The value of ks and ky were determined for various β-diketone complexes with β-diketone=acac, BA, DBM, TFAA and HFAA.The reactivities of the complexes fall as the β-diketone is varied in the sequence BA>acac>DBM>TFAA>HFAA, indicating that electronegative substituents in the β-diketone increase the trans-effect and therefore the strength of the Rh-O bonds.Since the ring opening is the rate-determining step in the reaction.It can be concluded that the complex containing the β-diketone with the largest trans-effect, which gives rise to the strongest Rh-O bonds, will undergo the slowest substitution.The effect of the substituents of the β-diketone (CF3, phenyl and CH3) on the trans-effect is discussed.
- Potgieter, J. H.
-
p. 369 - 376
(2007/10/02)
-
