Manufacture of Crystal Resonators Spectroscopic Standards,
Science
"Known" compound synthesized for first time Formaldehyde semicarbazone, a simple compound that for decades chemists have thought they were preparing but in fact were not, now has been made, apparently for the first time. The revelation and the synthesis are offered by Martin Pomerantz and Sarwat B. Khader of the University of Texas, Arlington, and Shmuel Bittner of Ben-Gurion University of the Negev, Beersheba, Israel [J. Org. Chem., 47, 2217 (1982)]. According to Pomerantz, many chemists still believe that formaldehyde semicarbazone can be made by mixing formalin solutions (40% aqueous formaldehyde) with semicarbazide, despite the existence of literature reports to the contrary. Nevertheless, these results apparently remain unknown to many. Indeed, chemists continue to use semicarbazide to trap formaldehyde, he says, and this reaction forms the basis for a photometric method of determining formaldehyde. The method apparently works, even though the analyst is not aware of the true identity of the colored species being measured. The first report of the preparation of formaldehyde semicarbazone using a reaction other than that between
formaldehyde and semicarbazide apparently also is in error, the Texas researcher says. This report, appearing in 1917, relies almost solely on an elemental analysis to identify the product. The misidentification is responsible for subsequently introducing into chemical data tables an erroneous value for the melting point of "formaldehyde semicarbazone." According to Pomerantz and his coworkers, whose work was supported by the Robert A. Welch Foundation and the University of Texas, the real formaldehyde semicarbazone can be prepared by mixing organic solutions of diazomethane and azodicarbonamide at room temperature according to the following equation: O
0
II
II
CH 2 N 2 + H2N^ C - N = N - C - N H 2 (CH 3 ) 2 SO or (CH 3 ) 2 NCHO
0
H2C=N-NH-C-NH2 The product's chemical and physical properties, they state, "leave no doubt that it is the heretofore unknown formaldehyde semicarbazone." •
Contractors for chemical synthesis sought Organizations that may wish to contract to provide syntheses of a variety of organic and inorganic compounds are being sought by the drug synthesis and chemistry branch of the division of cancer treatment of the National Cancer Institute. The primary focus, NCI says, is on synthesis of organic compounds. The project has a number of objectives: resynthesis of known compounds of varying degrees of complexity for confirmatory testing; resynthesis of a limited number of compounds in large enough amounts for extensive biological evaluation; synthesis of unique compounds with reported biological activity; synthesis of potential radiosensitizer/radioprotectors; and synthesis of unique compounds needed in NCI's intramural program. NCI says it intends to establish programs with laboratories as Quick
Reaction Work Order Contracts, master contracts negotiated and awarded to more than one contractor. Such contracts, it says, are designed to accomplish a specific task as quickly as possible. Some 300 compounds will be synthesized during each contract year, comprising about 40 individual work orders. NCI expects to issue individual work orders quarterly. NCI says that 10 to 12 master contracts will be awarded. Of these, 20% will be set aside for awards to small businesses (organizations of 750 employees or fewer). Those interested can obtain R F P NCI-CM-37554 by writing to Treatment Contracts Section, Research Contracts Branch, National Cancer Institute, Blair Bldg., Room 228,8300 Colesville Rd., Silver Spring, Md. 20910, attention: John A. Palmieri, contracting officer. •
Drug Manufacture Meets U.S.P. and other Pharmacopoeias
m
Produced by: Metallgesellschaft AG Operating Division Technical Processes Section Lithium Reuterweg 14 D 6000 Frankfurt a. M. 1 Tel. (0611) 159-1 Telex041225-Omgfd United States Representatives: The Ore & Chemical Corporation 605, Third Avenue New York, N.Y. 10016 Tel. (212) 949-1600 Telex 23 42 62 (RCA), 422 681 (ITT)
CIRCLE 27 ON READER SERVICE CARD June 7, 1982C&EN
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