Preparation of highly superacidic sulfated zirconia via combustion synthesis and its application in Pechmann condensation of resorcinol with ethyl acetoacetate

A novel zirconia-based catalyst, with high sulfur content (15% w/w) and preservation of the tetragonal phase of zirconia, was synthesized for the first time via a solution combustion synthesis approach. Such high sulfur content with preservation of the tetragonal phase has not been reported so far. The catalyst synthesis parameters were optimized using a probe reaction of Friedel–Crafts alkylation. The optimized catalysts, fuel-lean sulfated zirconia (FLSZ) and fuel-rich sulfated zirconia (FRSZ), were characterized by XRD, FTIR, TPD, EDAX, SEM, and BET surface area and pore size analysis. Further, the activity and stability of FLSZ was tested using a Pechmann condensation reaction between resorcinol and ethyl acetoacetate to produce 7-hydroxy 4-methyl coumarin selectively. A complete theoretical and experimental analysis is presented, and a kinetic model is developed for this reaction. The model explains the experimental data well. The characterization and reaction studies show that combustion-synthesized sulfated zirconia exhibits higher superacidity than the conventional sulfated zirconia catalyst

Rituximab and COVID-19 infection in patients with autoimmune rheumatic diseases – A real-world study from India

Introduction: Safety of rituximab (RTX) in autoimmune rheumatic diseases (AIRDs) has been a concern during this ongoing coronavirus (COVID-19) pandemic. Delayed worsening of COVID symptoms, increased hospital stays, and mortality has been reported among those infected post-RTX. This study describes the occurrence and course of COVID-19 infection among AIRD Indian patients who received RTX during this pandemic. Patients and Methods: Adult patients (≥18 years) with any AIRD, who received RTX between October 2019 and May 2021, were enrolled in this study. Patients satisfying the inclusion criteria were telephonically enquired about contracting confirmed COVID-19, its course, treatment, and outcome. Baseline parameters, immunoglobulin G level, vaccination, and comorbidity status before RTX were compared between the COVID-19 infected and noninfected patients to determine factors affecting the outcome. Results: Out of 1081 patients admitted during the study period, 218 patients received RTX. The mean age of these patients was 40.1 ± 14.2 years and comprised mostly of women (81.7%). Rheumatoid arthritis followed by lupus and anti-neutrophilic cytoplasmic antibodies-associated vasculitis was the predominant AIRD. Among the patients contacted (207/218 [94.9%]), 11 (5.3%) patients reported confirmed COVID-19 infections. Out of these, three (27.3%) had severe COVID-19 and one patient succumbed to it. Others became symptom-free after a mean duration of 14.4 ± 4.7 days of onset of symptoms. No significant difference among the baseline parameters observed predicted COVID-19 susceptibility. Conclusion: Among our AIRD patients treated with RTX, occurrence, and mortality of COVID-19 infection was low. Younger age of our patient cohort and female predominance might have contributed in reducing the severity of SARS-CoV-2 infection