Merck references, identifying

NMR spectra were recorded on Bruker Digital FT-NMR Avance 400 spectrometer (CDClj solvent) with TMS as internal reference. In the C spectra qnatemaiy, methylene and methyl carbons were identified using DEPT experiments. IR spectra were recorded on Perkin Elmer FT-IR spectrometer (KBr). Reactions were performed under dry nitrogew Melting points were measured on a Gallenkamp melting point apparatus. Sihca gel 60 (Merck) was used for column separations. TLC was conducted on standart conversion aluminium sheets pre-coated with a 0.2 mm layer of sihca gel. 

A somewhat difficult problem encountered by librarians of pharmaceutical houses and other institutions concerned with research on medicinal problems is that of tracing and identifying references to Merck literatmre. 

Special care has been taken to give complete references and, in general, each compound described has been identified by at least one reference. For compounds for which no specific literature indication is given, the reader is referred to the Merck Index. 

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