Bobranski

If a small Beckmann thermometer, similar to that used in the Sucharda-Bobranski method (p. 442) is available, the above method can be readily modified by replacing the tube T (Fig. 79) by an ordinary small boiling-tube without the side-arm A. The thermometer B and the stirrer S are fitted as in Fig. 79. The volume of solvent (usually ca 5 ml.) must of course cover the bulb of the thermometer. 

Molecular Weight by the Sucharda-Bobranski Method. (Semi micro Scale). 

MI21100 B. Bobranski and E. Sucharda Rocz. Chem., 1927, 7, 192 (Chem. Abstr., 1928,... 

Other compounds of this type which exist as tetrahedral intermediate-like tautomers include 1-benzyl-5,5-diethyl-3-lactyl barbituric acid (as [22]) (Bobranski and Sladowska, 1972), [23] (Grace et al., 1980), [24] (Patchorik et al., 1957 Grace et al., 1980), [25] (Temple et al., 1965) and [26] (McCapra and Leeson, 1976, 1979 Magerand Addink, 1979). 

The tubes used for the absorption of the I O and C02 formed in the combustion are of a very different type to those used in the macro method. Many workers use a straight tube (Fig. 71 (a)). Some use tubes of "the Bobranski and Sucharda pattern (b). The simplest tube is the modifica-... 

The Carius method can be worked on a micro (see Pregl, loc. tit.) or hemi-macro scale. Halogens can be estimated by other methods (see, inter alia, Bobranski and Sucharda, loc. tit.) in which the substance is completely oxidised in the dry state, Cl and Br being trapped in solid BaC03,1 in Na2S03 in a special apparatus. 

More details on synthesis, properties, and reactivity are provided in the review byLevinaandV elichko in 1960.4 Since that time further studies dealing with structure and conformation, spectral properties, and structure-activity relationships have been among the main advances in barbiturate chemistry. These topics were reviewed by Bobranski.5 This review presents the most important recent information on barbituric acids with special emphasis on their physicochemical properties. 

Bobranski et al. reported the resolution of optical isomers of 5-allyl-5-(2 -hydroxypropyl)barbituric acid by the fractional crystallization of their... 

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