Regiochemistry in alkylation, acylation and methoxycarbonylation of alkali salts from 2-substituted alkenylpropanedinitriles

High-Yield, Automated Radiosynthesis of 2-(1-{6-[(2-[18F]Fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile ([18F]FDDNP) Ready for Animal or Human Administration

“…In fact, the radiochemical yield of [ 18 F]FENE did not exceed 11%, even with prolonged heating and with little [ 18 F]FDDNP remaining in the basic reaction mixture (Table 2, entry 10). In addition to the possible reaction of naphthyl ketones in basic solution [32], the ethylidenemalononitrile moiety in [ 18 F]FDDNP, due to the extreme polarity of the double bond, may suffer dimerization [33,34]. Therefore, removing the base from the reaction mixture by using acid prevented these secondary reactions from happening during isolation and purification, thereby increasing the reproducibility of the synthesis.…”

Solvent-free 1H-tetrazole, 1,2,5,6-tetrahydronicotinonitrile and pyrazole synthesis using quinoline based ionic fluoride salts (QuFs): thermal and theoretical studies

“…In second step, QuF again abstracts proton from a-methyl group to promote dimerization via multistep sequence to afford 2-dicyanomethylene-6-methyl-4,6-bis(m-methoxyphenyl)-1,2,5,6-tetrahydronicotinonitrile (13) (Scheme 3). [27][28][29] Moreover, a reaction between acetylacetonate (13) and p-methoxyphenyl hydrazine hydrochloride (14) in the presence of QuF (4) under solvent-free condition afforded corresponding 3,5-dimethyl-1-(p-methoxyphenyl)-1H-pyrazole (15) in good yield (63%) as shown in the Scheme 4. The applications of QuFs in 1H tetrazole (7), 1,2,5,6-tetrahydronicotinonitrile (12) or pyrazole (15) formation signify their catalytic activity in organic reactions.…”

The unprecedented reaction of dimethylsulfonium methylide with Michael acceptors: synthesis of 1-substituted vinyl silanes and styrenes

“…The cis-relationship between the Me and the Ar in 8 was confirmed by 1D-NOE study (7.5% NOE enhancement was observed between the olefinic proton and the C-1 Me). The selectivity (5m vs. 8) could not be improved by changing the cation from Na to K. Fortunately, the reaction could be driven in the desired direction to give styrene 5m albeit in poor yield by the addition of MgBr 2 13 into the reaction medium prior to the addition of methyl iodide.…”

“…The benzyl sulfonium salts 22 and 23 were also prepared by heating a solution of benzyl bromide and tetrahydrothiophene or pentamethylene sulfide in hexanes followed by crystallization from EtOH-EtOAc. 1 H NMR and 13 C NMR spectra were recorded on a Bruker 200 MHz spectrometer. Spectra were referenced to residual chloroform (d 7.26 ppm, 1 H; 77.00 ppm, 13 C).…”

“…Diethyl (1-dimethyl[phenyl]silylvinyl)ethylmalonate 5c. Procedure as described for the preparation of 5b; yield 79% (found: C, 65.22; H, 8.27 2H, q, J = 7.1 Hz, MeCH 2 OCO), 4.12 (2 H, q, J = 7.1 Hz, MeCH 2 OCO), 5.67 (1 H,s,SiC=CH), 5.91 (1 H,s,m,Ar); d C (50 MHz, CDCl 3 ) −0.32 (2 C), 9.44, 13.92 (2 C), 28.57, 61.07 (2 C), 63.72, 127.42 (2 C), 128.53, 130.80, 134.02 (2 C), 140.09, 147.52 and 171.00 (2 C); m/z (EI) 333 (M + − Me, 33%), 303 (5), 275 (16), 271 (59), 259 (13), 233 (12), 215 (32), 187 (42), 159 (87), 153 (48), 135 (100), 141 (33), 125 (46), 121 (22), 107 (20), 105 (71), 95 (38), 91 (30), 77 (33) and 75 (73).…”