MedChem Designer™ – free chemical structure drawing program
MedChem Designer 3.0 is a free chemical structure drawing program. MedChem Designer can open SMILES, SDF, MOL, CSK, and RXN file types. Up to 32 compounds can be displayed in one window. Images can be exported in SMILES, SD, MOL, CQF, bitmap, JPG, or PNG formats. Various properties e.g., logP, logD, topological polar surface area (TPSA), can be quickly and easily computed. Additionally, structure images and predicted properties can be exported in Excel format. One can also copy a SMILES string e.g., from the Wikipedia page for aspirin, and paste it into MedChem Designer. Reactions can be sketched and converted to SMIRKS strings or saved as RXN files for use in other programs. The optical structure recognition tools allows one to copy an image into MedChem Designer.