Title:Identification and Synthesis of Major Impurities Formed During the Synthesis of Trifloxystrobin and Kresoxim-methyl Fungicides
VOLUME: 12 ISSUE: 5
Author(s):Pasumpon Kamaraj, Nakita Antao, Apoorva Singh, Vijay Satam, Subhash Kadam, Venkatesh M. Prabhu, Rama Mohan Hindupur and Hari N. Pati
Affiliation:Process Chemistry Division, Advinus Therapeutics Ltd., 21 & 22 Phase II, Peenya Industrial Area, Bangalore - 560058, Karnataka, Índia.
Keywords:Fungicide, impurities, Kresoxim-methyl, pharmacophore, strobilurins, Trifloxystrobin.
Abstract:During process development of Trifloxystrobin and Kresoxim-methyl fungicides, two impurities were identified. These impurities were isolated and characterized using LCMS, IR, 1H NMR, 13C NMR and elemental analysis. Structures of the impurities were further unambiguously confirmed by their independent synthesis. Structure of both impurities revealed that they possess methyl (E)-methoxyiminoacetate pharmacophore, responsible for antifungal activities of strobilurins, in combination with arylmethyl (E)-methoxyiminoacetate framework.
The two synthesis essay questions below are examples of the question type that has been one of the three free-response questions on the AP English Language and Composition Exam as of the May 2007 exam. The synthesis question asks students to synthesize information from a variety of sources to inform their own discussion of a topic. Students are given a 15-minute reading period to accommodate the additional reading required for the question.
Below is a sample synthesis essay question, sample scoring guidelines, comments from the Chief Reader about the sample student essays, seven sample student responses, and scoring commentary for each sample.
Approximately 300 AP English Language and Composition students from eight schools in New York, Maine, Texas, Tennessee, Washington, Florida, and New Mexico wrote responses to this synthesis topic. Students from these schools were given a 15-minute reading period followed by a 40-minute writing period in which to complete the sample synthesis assignment.
An additional sample synthesis essay question is provided here.