Methyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate

Abstract

The 3-cyclo­hexene units adopt envelope conformations in each of the two independent mol­ecules that comprise the asymmetric unit of the title compound, C20H16F2O3. The dihedral angles between the two fluoro­phenyl rings are 79.7 (2) and 73.7 (2)° in the two mol­ecules. In one of the mol­ecules, two C—H groups of the cyclo­hexene ring are disordered over two sets of sites in a 0.818 (13):0.182 (13) ratio, the major and minor components corresponding to the two enanti­omeric forms of the mol­ecule. Weak inter­molecular C—H⋯O inter­actions help to stabilize the crystal structure.

A chalcone showing positional disorder, two related diarylcyclohexenones showing enantiomeric disorder and a related hydroxyterphenyl, all derived from simple carbonyl precursors

“…The type 1 molecules are linked by inversion-related C-HÁ Á ÁO hydrogen bonds, while the type 2 molecules are linked by inversion-related C-HÁ Á Á(arene) hydrogen bonds, so forming dimers lying across ( It is of interest briefly to note the structures of some related cyclohexenone and terphenyl derivatives (see Scheme 3). Compound (V), prepared using the cycloaddition reaction between (2E)-1,3-bis(4-fluorophenyl)prop-2-en-1-one and methyl 3-oxobutanoate, also crystallizes with Z 0 = 2 as a racemic mixture of the (1R,6S) and (1S,6R) forms, although the stereochemistry of the compound was not mentioned anywhere in the original report (Fun et al, 2010). Compound (VI), the precursor for compound (IV) reported here, was described (Dutkiewicz et al, 2011) as having a three-dimensional supramolecular structure, built from C-HÁ Á ÁO, C-HÁ Á ÁF and C-HÁ Á Á(arene) hydrogen bonds; however, the C-HÁ Á ÁO contact has a D-HÁ Á ÁA angle of only 130 and so cannot be regarded as structurally significant (Wood et al, 2009), and it is well established (Howard et al, 1996) that F atoms bonded to C atoms are not effective acceptors of hydrogen bonds.…”

“…9). When a diarylcyclohexenone of type (B) (Scheme 1) is oxidized using iodine in methanol, rather than a quinone as used here for the formation of compound (IV), the resulting terphenyls carry a 5-methoxy substituent instead of the 5-hydroxy substituent observed in (IV), as exemplified by compounds (IX) (Fun et al, 2012) and (X) (Fun et al 2011) (see Scheme 3). Neither of compounds (IX) and (X) contains an intramolecular O-HÁ Á ÁO hydrogen bond and, in each, the carbonyl substituent is approximately orthogonal to the adjacent ring, as found here in (III) but not in (IV).…”

Synthesis, Characterization and Crystal Structures of 3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide and 3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide

“…In view of the importance of pyrazolines and in continuation of our work on synthesis of various derivatives of 4,4'-difluoro chalcones [11][12][13][14][15][16][17][18], we report the synthesis and crystal structures of new 3,5-bis(4-fluorophenyl)-4,5-dihydropyrazoles substituted at position 1 with carboxamide or carbothioamide groups (Figure 1). …”

Crystal and Molecular Structure Studies of Ethyl 4-(4-Hydroxyphenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate and Ethyl 4-(3-Bromophenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate

“…The more common application is found in preparation of 3,5-diaryl-6-carbethoxycyclohexanones, efficient synthons in building spiro compounds [5], or intermediates in the synthesis of benzisoxazoles, or carbazole derivatives [6,7], via 1,3-Michael addition of ethyl acetoacetate. Crystal structures of (8RS, 9SR)-ethyl 4-(3-bromothien-2-yl)-6-(2-furyl)-2-oxocyclohex-3-ene-1-carboxylate [8], ethyl 4-(3-bromo-2-thienyl)-2-oxo-6-phenylcyclohex -3-ene-1-carboxylate [9], (R, S)-methyl 3-methyl-5-oxo-1-phenylcyclohex-3-ene-1-carboxylate [10], rac-ethyl 3-(3-bromo-2-thienyl)-2-oxo-6-(4-propoxyphenyl)cyclohex-3-ene-1-carboxylate [11], (±)-ethyl 6-(6-methoxy-2-naphthyl)-4-(4-methylphenyl)-2-oxocyclohex-3-ene-1-carboxylate [12], ethyl 6-(6-methoxy-2-naphthyl)-2-oxo-4-(2-thienyl)cyclohex-3-ene-1-carboxylate [13], (1RS,6SR)-ethyl 4-(4-chlorophenyl)-6-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate toluene hemisolvate [14], ethyl 4-(2,4-dichlorophenyl)-6-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate [15], ethyl 4,6-bis (4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate [16] and methyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate [17] have been reported. In view of the pharmacological importance of these derivatives, crystal and molecular structure studies of two new derivatives of cyclohex-3-ene-1-carboxylates, (I) and (II) (Figure 1), are reported, and expected to be useful for the docking studies.…”