A. V. Sanin

Preparation of α, β-Unsaturated Ketones Bearing a Trifluoromethyl Group and Their Application in Organic Synthesis

, Andrei V. Sanin, Elizabeth S. BalenkovaDepartment of Chemistry, Moscow State University, 119899 Moscow, RussiaTel.: +7 (095) 939-43-94; Fax: +7 (095) 932-88-46; E-mail: Nen@acylium.chem.msu.suReceived: 9 December 1996 / Accepted: 28 March 1997 / Published: 1 December 1997Abstract: The approaches to the synthesis of α,β-unsaturated CF

REACTION OF TRIFLUOROMETHYL- CONTAINING ENONES WITH THIOPHENOL DERIVATIVES

The reaction of trifluoromethyl-containing enones with thiophenol derivatives has been studied. Reactions with 4-methylthiophenol proceed with the formation of either ketosulfides or a pyran derivative. Reactions of trifluoromethyl-containing enones with 2-mercaptobenzaldehyde lead to 3-trifluoroacetyl-substituted 2H-thiochromenes.

SYNTHESIS AND STEREOCHEMISTRY OF TRIFLUOROMETHYL-CONTAINING ISOXAZOLIDINES

The reaction of trifluoromethyl-containing enones with hydroxylamine under various conditions is studied. The products in basic medium are equilibrating mixtures of isoxazolidine diastereomers in an ∼1∶1 ratio. The energy of the nitrogen atom inversion barrier in these compounds is 50–60 kJ/mol. Broadened signals are observed at room temperature in the1H and13C NMR.

Synthesis of trifluoromethyl derivatives of pyrazolidine- and 2-pyrazoline-1-carboxamides and pyrazolidine- and 1-pyrazoline-carbothioamides

The reactions of enones containing trifluoromethyl groups with semicarbazide in basic media proceed unequivocally to give pyrazolidine-1-carboxamides. The direction of the reactions of these enones with thiosemicarbazide depends on their structure; the reaction products are pyrazolidine- and 2-pyrazoline-1-carbothioamides. An enone containing a CF3 group and an ethoxy group capable of replacement reacts with semicarbazide to give 2-pyrazoline-1-carboxamide and with thiosemicarbazide to give the double addition product, 5-(1-thiosemicarbazido)-2-pyrazoline-1-carbothiamide.

Synthesis of 1,5-benzodiazepine heterocycles containing a trifluoromethyl group

Summary2,3-Dihydro-1,5-benzodiazepines containing a trifluoromethyl group were obtained by the reaction of α,β-unsaturated ketones CF3COCH=CR1R2 with o-phenylenediamine.