Synthesis of functionalized bicyclic pyridones containing dithiocarbamate group using thioazlactones, diamines and nitroketene dithioacetal

An efficient method for the synthesis of highly substituted bicyclic pyridone derivatives containing dithiocarbamate group is reported via a one-pot three-component reaction of 2-(alkylthio) thioazlactones, diamines and nitro ketene dithioacetal in EtOH under catalyst-free conditions. The reaction proceeds via a domino amidation/intramolecular 1,4-addition-type Friedel-Crafts alkylation reaction to afford the corresponding fused bicyclic pyridones with high yields and diastereselectively. The desired products are fully characterized by FT-IR, 1H and 13CNMR, CHN and single crystal X-ray diffraction analyses.

S-[2-(2,2-Dimethylpropanamido)-3-(trifluoromethyl)phenyl]N,N-diisopropyldithiocarbamate

In the title compound, C19H27F3N2OS2, the dihedral angle between the benzene ring and dithiocarbamate group is 67.00 (9)° and a weak intramolecular N—H...S interaction generates anS(7) ring. Thetert-butyl group is disordered over two orientations in a 0.628 (14):0.372 (14) ratio. In the crystal, inversion dimers linked by pairs of weak C—H...O interactions generateR22(20) loops and the aromatic rings of neighbouring pairs of molecules are involved in very weak π–π stacking interactions [centroid–centroid separation = 4.0042 (13) Å].

The Experimental Study and Mechanism Analysis on Flotation Separation of Tetradymite and Pyrite

The experimental results of flotation of pure tetradymite and pyrite show that HL-1 is an efficient collector for tetradymite flotation. Comparing to the butyl xanthate, HL-1 has stronger collector ability and higher selectivity. It solves the common problem of the separation of tetradymite and pyrite. The difference of adsorption quantity is consistent with results of the single mineral flotation test. Through the measurements of adsorption, zeta-potential, and FTIR spectral analysis, the flotation mechanism of tetradymite with HL-1 has been discussed. It is concluded that the adsorption of HL-1 on tetradymite surface is chemical adsorption through the dithiocarbamate group of the collector chelating the Bi (III) of tetradymite to form metal complex.

Crystal structure of 4-(2,2-dimethylpropanamido)pyridin-3-ylN,N-diisopropyldithiocarbamate

In the title compound, C17H27N3OS2, the amide group is approximately coplanar with the pyridine ring [dihedral angle = 1.6 (1)°], whereas the dithiocarbamate group is nearly perpendicular to the pyridine ring [dihedral angle = 76.7 (1)°]. In the crystal, pairs of weak C—H...O hydrogen bonds link the molecules into inversion dimers.