Preparation of 3, 3', 5, 5'-tetrakis(1-methyl)biphenyl-4,4'-diol ( 4) Propofol (1) (5 g, 28 mmol) was charged into water (150 mL) followed by addition of FeCl 3 (5.6 g, 30.3 mmol) and the reaction mixture was heated at 90 o C for 1 h. Reaction mixture was allowed to cool to room temperature and extracted with ethyl acetate (2 × 75 mL). Combined organic layer was dried over sodium sulphate, filtered and concentrated to give the crude product which was used as such for the next step. To a solution of crude residue in THF (45 mL) and MeOH (5 mL), was added sodium borohydride (3.2 g, 84 mmol) and reaction mixture was stirred
In the field of rechargeable batteries, redox organic compounds have attracted huge attention owing to their eco-friendliness, resource abundance, good flexibility, and low cost. However, the high solubility of the organic compounds in electrolytes results in poor cell performance. In this paper, we report that a cross-linked naphthalene diimide-based polymer, which is a three-dimensional network structure, exhibits outstanding cell performance in organic batteries. The polymer is synthesized by the imidization condensation of naphthalene-1,4,5,8-tetracarboxylic dianhydride (NDA) and 4-vinylaniline to form N,N′-di(4′-vinylphenyl)naphthalene-1,4,5,8-dicarboxydiimide (DVP-NDI) and by subsequent radical polymerization to a cross-linked DVP-NDI (CL-DVP-NDI) polymer. The cross-linking of the polymer is characterized using infrared and solid-state 13 C nuclear magnetic resonance spectroscopy. Thermogravimetric analysis shows that the polymer with a three-dimensional network structure exhibits better thermal stability than an organic molecule. The solubility test indicated that the CL-DVP-NDI polymer can suppress the dissolution of the polymer in organic electrolytes. The discharge capacity of the CL-DVP-NDI electrode is 121.3 mAh g −1 at a C-rate of 0.2 C. The cycle-life performance of the Li||CL-DVP-NDI cell is 84% remaining after 200 cycles at a charging−discharging rate of 1 C.
An
efficient, short manufacturing process for fenspiride hydrochloride
is reported. Nitro-aldol condensation is the key reaction in the developed
process. Improved routes to key building blocks are demonstrated by
expedient multikilogram production. Hazardous reactions are avoided.
API produced following this new route meets the quality requirement
NLT 99.70% purity by HPLC with any individual impurity NMT 0.10% with
very good yield.
Quinoxaline-based novel acid-responsive probe Q1 was designed on the basis of a conjugated donor-acceptor (D-A) subunit. Q1 shows colorimetric and fluorometric changes through protonation and deprotonation in dichloromethane. With the addition of the trifluoroacetic acid (TFA), UV-vis absorption spectral changes in peak intensity of Q1 was observed. Moreover, the appearance of a new peaks at 284 nm 434 nm in absorption spectra with the addition of TFA indicating protonation of quinoxaline nitrogen and form Q1.H+ and Q1.2H+. The emission spectra display appearance of new emission peak at 515 nm. The optical property variations were supported by time resolved fluorescence studies. The energy band gap was calculated by employing cyclic voltammetry and density functional calculations. Upon addition of triethylamine (TEA) the fluorescence emission spectral changes of Q1 are found to be reversible. Q1 shows color changes from blue to green in basic and acidic medium, respectively. The paper strip test was developed for making Q1 a colorimetric and fluorometric indicator.
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