Tables of compounds, 4,5-disubstituted

Table 2 shows the structure-activity relationships of the compound library of the 2,5-disubstituted 1,3,4-oxadiazoles 25-43 against the enzyme... 

Synthesis of 2,4-disubstituted 1,3,5-triazines bearing a single type of substituent The preferred routes to several of these compounds are summarized in Table 21. 

Thiadiazoles undergo a facile reaction with electrophiles on the annular nitrogen atoms. In an extensive study, the quaternization of 2,5-disubstituted 1,3,4-thiadiazoles with methyl iodide was compared with quaternization in the pyridazine series. The influence of the alkyl substituents on product-distribution was less in the thiadiazole series than in the pyridazine series, probably due to the difference in geometry of the two compounds. The conditions chosen for the quaternization were such that the reaction was irreversible and the product distribution therefore kinetically controlled. Some of the results obtained are summarized in Table 13 (73ACS391). NMR data on these compounds are presented in Section 4.27.2.3.4. 

Disubstituted Analogs Disubstituted DCK analogs were also developed and screened for inhibition of HIV replication in H9 lymphocytes (Table 9-3). " 4-Methyl-5-methoxy DCK (69) was the most promising compound and was similar to 4-methyl DCK (53) and much better than DCK (2) in the same assay. Dimethyl DCKs 63 (3,4-dimethyl), 67 (3,5-dimethyl), 68 (4,5-dimethyl), and 72 (4,6-dimethyl) showed about 20-fold lower activity compared with 2. Among other 3,4-disubstituted compounds, 3-chloro-4-methyl (64) and 3,4-cyclohexano... 

The Woodward-Hoffmann rules predict that thermolysis of an exo-exo or endo-endo 2,4-disubstituted bicyclobutane will result in the formation of a cis-trans disubstituted butadiene, whereas endo-exo substitution will lead to the formation of a trans-trans butadiene. The data presented in Table 5 show that to a large extent the thermolysis of compounds 93 and 94 does indeed display a steric course which is in accordance with the Woodward-Hoffmann rules. 

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