Enantioselective Synthesis of Antiepileptic Drug: (-)-Levetiracetam-Synthetic Applications of the Versatile New Chiral N-Sul�nimine

We report an asymmetric synthesis of (-)-Levetiracetam (1) in six steps starting from versatile new chiral N-sul�nimine (3). e key step, stereoselective 1,2-addition of ethylmagnesium bromide (EtMgBr) to chiral N-sul�nimine derived from (R)-glyceraldehyde acetonide and (S)-t-BSA, gave the corresponding sulfonamide (2) in high diastereoselectivity. Simultaneous deprotection and deacetylation followed by NaIO 4 cleavage and reduction gave -amino alcohol (6). Subsequent reactions yielded the targeted compound levetiracetam (1)

Detection, Isolation and Characterization of Principal Synthetic Route Indicative Impurity in Lansoprazole

An unknown impurity in lansoprazole (2-[[[3-methyl-4-(2, 2, 2-trifluoroethoxy)-2-pyridyl] methyl] sulfinyl] benzimidazole) was detected by HPLC and was identified as des-(trifluoroethoxy) lansoprazole, an principal synthetic route indicative impurity of lansoprazole. Lansoprazole was subjected to different ICH prescribed stress conditions like hydrolysis, oxidation, photolysis and thermal degradation conditions to enrich the impurity. The impurity was enriched by using acid catalytic degradation, isolated by using preparative HPLC and characterized (FTIR, MS and NMR). Limit of Detection (LOD) and Limit of Quantification (LOQ) are found to be 0.014% and 0.035% respectively

Enantioselective Synthesis of Antiepileptic Agent, (−)-Levetiracetam, through Evans Asymmetric Strategy

A practical and efficient enantioselective synthesis of antiepileptic drug, (−)-Levetiracetam, has been described in five steps (33.0% overall yield) and high optical purity (99.0% ee), using Evans asymmetric strategy for α-alkylation of carbonyl functionality as the key step. The simplicity of the experimental procedures and high stereochemical outcome make this method synthetically attractive for preparing the target compound on multigram scales

Enantioselective Synthesis of Antiepileptic Drug: (-)-Levetiracetam—Synthetic Applications of the Versatile New Chiral N-Sulfinimine

We report an asymmetric synthesis of (-)-Levetiracetam (1) in six steps starting from versatile new chiral N-sulfinimine (3). The key step, stereoselective 1,2-addition of ethylmagnesium bromide (EtMgBr) to chiral N-sulfinimine derived from (R)-glyceraldehyde acetonide and (S)-t-BSA, gave the corresponding sulfonamide (2) in high diastereoselectivity. Simultaneous deprotection and deacetylation followed by NaIO4 cleavage and reduction gave β-amino alcohol (6). Subsequent reactions yielded the targeted compound levetiracetam (1)

A novel anti-HER2 anthracycline-based antibody-drug conjugate induces adaptive anti-tumor immunity and potentiates PD-1 blockade in breast cancer

Abstract Increasing evidence suggests that antibody-drug conjugates (ADCs) can enhance anti-tumor immunity and improve clinical outcome. Here, we elucidate the therapeutic efficacy and immune-mediated mechanisms of a novel HER2-targeting ADC bearing a potent anthracycline derivate as payload (T-PNU) in a human HER2-expressing syngeneic breast cancer model resistant to trastuzumab and ado-trastuzumab emtansine. Mechanistically, the anthracycline component of the novel ADC induced immunogenic cell death leading to exposure and secretion of danger-associated molecular signals. RNA sequencing derived immunogenomic signatures and TCRβ clonotype analysis of tumor-infiltrating lymphocytes revealed a prominent role of the adaptive immune system in the regulation of T-PNU mediated anti-cancer activity. Depletion of CD8 T cells severely reduced T-PNU efficacy, thus confirming the role of cytotoxic T cells as drivers of the T-PNU mediated anti-tumor immune response. Furthermore, T-PNU therapy promoted immunological memory formation in tumor-bearing animals protecting those from tumor rechallenge. Finally, the combination of T-PNU and checkpoint inhibition, such as α-PD1, significantly enhanced tumor eradication following the treatment. In summary, a novel PNU-armed, HER2-targeting ADC elicited long-lasting immune protection in a murine orthotopic breast cancer model resistant to other HER2-directed therapies. Our findings delineate the therapeutic potential of this novel ADC payload and support its clinical development for breast cancer patients and potentially other HER2 expressing malignancies