Merck Darmstadt

Technical Informationsfor Crop Protection, E. Merck, Darmstadt, Germany, 1964. 

The biotin market is divided between agricultural and human use, with —90% of biotin used in the animal health care market and —10% for the human nutritional market. The major producers of biotin are Hoffmann-La Roche, Lon2a, E. Merck-Darmstadt, Rhc ne-Poulenc, Sumitomo Pharmaceutical, E. Sung, and Tanabe Seiyaku (100). Worldwide production of biotin in 1994 was approximately 60 metric tons. The Hst price for pure biotin in 1995 was — 7.00/g whereas, the Hst price for technical feed-grade biotin was — 5.50/g. Biotin is used in various pharmaceutical, food, and special dietary products, including multivitamin preparations in Hquid, tablet, capsule, or powder forms. One of the commercially available products of i7-biotin is Britrit-1, which is a 1% biotin trituration used in food premixes. 

Oicyclopentadiene, obtained from the Aldrich Chemical Company, Inc. (or E. Merck, Darmstadt, FRG), was cracked just prior to use according to the procedure of Fieser and Williamson, to give the monomer, bp 40-42°C. 

The catalyst, 3-benzyl-5-(2-hydroxyethyl )-4-methyl-l, 3-thiazoHum chloride, is supplied by Fluka AG, Buchs, Switzerland, and by Tridom Chemical, Inc., Hauppauge, New York. The thiazolium salt may also be prepared as described below by benzylation of 5-(2-hydroxyethyl)-4-methyl-l,3-thiazole which is commercially available from E. Merck, Darmstadt, West Germany, and Columbia Organic Chemicals Co., Inc., Columbia, SC. The acetonitrile used by the checkers was dried over Linde 3A molecular sieves and distilled under nitrogen, bp 77-78°C. The same yield of thiazolium salt was obtained by the checkers when benzyl chloride and acetonitrile from commercial sources were used without purification. 

Scoops of solid potassium tcrt-butoxide (purchased from E. Merck, Darmstadt, and specified to be at least 95% pure) were added over 20-30 minutes by temporarily removing the drying tube. At the beginning of the reaction much heat is evolved therefore the base should be added in small portions in order to keep the temperature below 10°. During the addition of the base, a precipitate is formed. 

Alumina Number 1076, aktiv basisch, for chromatography (E. Merck, Darmstadt) was usually employed. Occasionally, when alumina Number 1077, aktiv neutral, from the same company, was used, a longer reaction time was required (compare Note 15). 

Commercial formamide (E. Merck, Darmstadt) was used. The use of a large excess of formamide with respect to the sulfinate is required in order to obtain the yield specified. ... 

Dimethoxyethane and triethylamine, both in zur Synthese quality, were purchased from E. Merck, Darmstadt. Diethyl ether was distilled from phosphorus pentoxide and stored over sodium wire. 

Eractogel TSK Hydrophilic Gel Media—Tools for Chromatographic Techniques in Biotechnology, Merck, Darmstadt, ERG. 

R)- and (S)-2-I Iydroxy-1.2,2-triphenylcthyl acetate are commercially available from Merck, Darmstadt, Germany and from Newport Pharmaceuticals, Ireland. The (R)-enantiomer is also available from Fluka and Chiron. 

Y,.Y- Dimethylforrnamide was purchased from Merck, Darmstadt and dried by standing over molecular sieves (Union Carbide, type 4A). 

Fig. 14.2H NMR spectra of LPE, isothermally crystallized from the melt at 396 K (Mw as 100000, Mw/Mn as 10, Merck, Darmstadt) at 55 MHz obtained from a complex FT of the solid echo for various temperatures...

Analytical-grade (pro analyst) sodium cyanide was purchased by the submitters from Merck, Darmstadt, Germany, and dried for 24 hours in a vacuum desiccator containing potassium hydroxide pellets. The checkers obtained sodium cyanide from Fisher Scientific Company and dried the reagent in the same manner. 

The submitters used Activity I (Brockmann) Camag alumina, which was purchased from Hopkins and Williams. The checkers used comparable material obtained from E. Merck Darmstadt, Germany. 

Adamantanol is available from the following three suppliers Aldrich Chemical Company, Inc., Fluka AG, Buchs, Switzerland E. Merck, Darmstadt, Germany. It may also be prepared from adamantane by bromination to 1-bromoadamantane and hydrolysis. Adamantane is sold by the same three suppliers. 

Silica gel 60 having particle sizes ranging from 0.063 to 0.200 mm. (70-230 mesh) is suitable. It may be purchased from Brinkmann Instruments, Inc., or E. Merck, Darmstadt, Germany. The submitters report that silica gel of this type normally contains ca. 5% water, which may be removed by drying at 300° for several hours. Somewhat better yields are obtained when the silica gel is dried in this manner before use. 

Merck Darmstadt F254+366 Silica Gel 60 F254 60 6 5-40 254 Organic... 

Merck Darmstadt oxide 60 F254 PLC plates aluminum 150 6 5 ... 

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