Radio isomer

Form—for a given parent, specifies different salt forms, different radio isomers, or different formulations. 

Compound ID—combination of Parent ID, Form, and Check. Uniquely identifies the complete structure, including salt, radio isomer, or formulation. 

For the FgS2 isomers cf. Seel, F. Adv. Inorg. Chem. Radio-... 

The number of acids possessing the same atomic weight, and belonging to this division, is determined, first, by the comple mentary variation of the two alcohol radios, and, secondly, by the number of possible isomers of these radicals. The two lowest terms of the series are alone incapable of isomeric modification by either of the causes mentioned. 

Both the 2,6- and the 3,5-isomers, as the N,N-dimethyl homologues, have been looked at as potential radio-halogen recipients in the search for positron-emitting brain blood-flow indicators, as discussed in the recipe for IDNNA. Both were made from the appropriate nitrostyrene via the corresponding phenylacetone. 

There are three other dimethoxyamphetamine isomers known, and each has been explored chemically as to its reactivity with elemental bromine. With 2,3-DMA, a mixture of the 5-Br-2,3-DMA and 6-Br-2,3-DMA was formed with 2,6-DMA, 3-Br-2,6-DMA was formed and with 3,5-DMA, a mixture of 2-Br-3,5-DMA and the 2,6-dibromo product was produced. The bromination of 2,5-DMA is, of course, the preferred procedure for the synthesis of 4-Br-2,5- DMA, or DOB, q.v. None of these positional isomers has ever been put into man, but 3-Br-2,6-DMA and the iodo-counterpart have been explored as potential radio-fluorine carriers into the brain. This is all discussed in the 3,4-DMA recipe. 

The mixture of anomers of 3, 5 -dibenzyl-2 -deoxy-2, 2 -difluorocytidine 76 obtained has been separated by crystallization from ethyl acetate. Deprotection with methanolic ammonia yielded 71b containing, after radio-HPLC, 99.8% of the desired / -isomer of >99.4% radiochemical purity. The overall radiochemical yield was 10.2%. 

The yield of C7 products, which might be indicative of isomerization processes via one C-C bond cleavage in the ring, is about the same as that of Cg products formed in the radio lysis of cyclobutane (10-20 %). However the effect of oxygen is small for three of the four isomers of butylcyclopropane (except in the case of the s-butyl isomer) while for butylcyclobutane the effect is more pronounced, probably indicating that for the cyclopropane the monomolecular isomerization proceeds with a higher probability than in the radiolysis of four-membered rings. 

Azaconazole, C4abelled at the 2-caibon of the dioxolane ring (Fig. 1), was obtained from the Janssen Radiosynthesis Group. It showed a specific activity of 449 kBq/mg (12.1 pCi/mg) and a radiochemical purity exceeding 96%, as determined by radio-HPLC. The impurity was C-R 33 277, the 4H-1,2,4-triazole isomer of azaconazole. Unlabelled azaconazole was found to have a purity in excess of 99%. 

A barrier-isomerization of about 2000 cm-1 (Fig. 24) allows the metastable cyanide isomer, MgCN, to exist [26], Anderson et al. [109] recorded the millimeter wave spectrum of the X2E+ state of MgCN along with very strong MgNC lines. These data allowed the identification of the MgCN isomer in the carbon star IRC + 10216 by radio astronomers [110]. 

Tc and other isotopes and isomers of technetium are nuclides of medium radio-toxicity [26] licensing limits, annual limits of intake and maximum permitted air concentrations arc compiled in Table 5.4.A. 

Figure 7 shows the spectra for xylene isomers obtained from a microfabricated radio-frequency... 

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