Central Washington University 2 articles published in JoVE Chemistry A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products Christopher E. Malmberg1, Stephen Chamberland2 1Department of Chemistry, Central Washington University, 2Department of Chemistry, Utah Valley University Here, we present a protocol for direct, early stage guanidinylation that enables rapid total synthesis of aminoguanidine-containing small organic molecules. An advanced synthetic intermediate used in the synthesis of a blood coagulation factor XIa inhibitor was prepared using this protocol. Engineering Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies Michael Jackson1,3, Lyndon R. Zink2 1Department of Physics, Central Washington University, 2Department of Physics, University of Wisconsin-La Crosse, 3College of Science and Technology, Millersville University We describe the generation of far-infrared radiation using an optically pumped molecular laser along with the measurement of their frequencies with heterodyne techniques. The experimental system and techniques are demonstrated using difluoromethane (CH2F2) as the laser medium whose results include three new laser emissions and eight measured laser frequencies.