The Synthesis of 4-Alkyldithioate-5-hydroxy-3-methyl-1-phenylpyrazoles

1,5-Bis(4-dithiocarboxylate-5-hydroxypyrazolyl)pentane derivatives of 5-pyrazolones

“…The enolic 5-hydroxypyrazolyl-4-dithiocarboxylate structure of compounds 2b-c and 6b-c was assigned on the basis of the 1 H and 13 C nmr data. The 1 H nmr spectra shows a downfield singlet at 12.30-13.74 ppm due to the enolic proton of the 5-hydroxy group, while in the 13 C nmr spectra the thiocarbonyl, the C-3, C-4 and C-5 signals of the pyrazole ring are observed around 213, 146, 111 and 158 ppm respectively, in agreement with previously reported values [4][5][6][7][8][9][10]16]. Preliminary studies on the chelating and extractives properties of 6b-c with Cu(II) confirm the tetradentate character of the synthesized compounds by formation of a 1:1 metal/ligand complex.…”

“…It is known that the reaction of active methylene compounds with carbon disulfide and alkyl halides affords alkyldithiocarboxylate or ketene dithioacetal derivatives, depending on the stoichiometry of the reaction or on the nature of the base employed [1][2][3]. With 5-pyrazolones 1, the pyrazolyl-4-alkyldithiocarboxylates 2 or the ketene dithioacetals 3 are obtained and reactions can be achieved in n-butyllithium-THF, sodium acetate-DMF [4][5][6][7] or under phase-transfer catalysis (PTC) conditions [8][9][10].…”

“…Because of our interest on the chelating and extractive properties of the pyrazolyldithiocarboxylates 2, we have studied the reaction of 5-pyrazolones with 1,2-dibromoethane and 1,3-dibromopropane in order to get bispyrazolyl derivatives 6 with tetradentate complexing properties. However, independant of stoichiometry conditions of the reaction, the only isolated compounds were the cyclic ketene dithioacetals 7, probably due to the stability of the five member dithiolane and six member dithiane cycle [4,8,9].…”

1-Alkyl-4-Ethoxythiocarbonyl-5-Hydroxy-3- Methylpyrazole : Synthesis , Copper Complexes and Solvent Extraction Studies

“…Elemental analysis of carbon, hydrogen, nitrogen and sulfur is in agreement with a molecular formula of C30H50N4O4S2CU and C38H66N4O4S2CU for the complexes 2a and 2b, respectively, meaning that the ligands are bidentate and form complexes of the type Cu(ETCP)2-According to previously reported results with analog dithiocarboxylate derivatives [14][15][16][17][18][19][20][21], oxygen attached to carbon 2 of pyrazole and sulfur of the methoxythiocarbonyl group are responsible for the Cu (II) chelation. Elemental analysis of carbon, hydrogen, nitrogen and sulfur is in agreement with a molecular formula of C30H50N4O4S2CU and C38H66N4O4S2CU for the complexes 2a and 2b, respectively, meaning that the ligands are bidentate and form complexes of the type Cu(ETCP)2-According to previously reported results with analog dithiocarboxylate derivatives [14][15][16][17][18][19][20][21], oxygen attached to carbon 2 of pyrazole and sulfur of the methoxythiocarbonyl group are responsible for the Cu (II) chelation.…”

Polyvinylic Derivatives of 4-Allyldithiocarboxylate-5-Hydroxy-3-Methyl-1- Phenylpyrazol

“…At the end of the reaction, a flowable orange to red liquid was formed, becoming to a glasslike solid 2 at room temperature (Ec. The displacement of the CH 2 S signal to higher field during the polymerization is in agreement with the chemical shift observed when this group is part of a saturated alkyl chain (3.35-3.56 ppm) (1,4). Following the same methodology, the 4-allyldithiocarboxylate 1 was bulk copolymerized with styrene or acrylamide , using a 1:1 molar ratio of the monomers.…”