Isothiazoles, synthesis

Androstano[2,3-g]pteridine, 2,4-diamino-synthesis, 3, 317 Androsteno[ 17,16-d]isothiazole synthesis, 6, 167... 

Adams and Slack s second isothiazole synthesis involved the preparation of j3-iminothiobutyramide (9) from the nitrile 8 and cycliza-... 

Isothiazole synthesis Isothiazole can be prepared from thioamide in the following way. 

Condensation of Nitriles and Dialkyl Sulphites. (Type C).—A novel isothiazole synthesis involves the interaction of phenylacetonitrile anion, generated in the presence of sodamide, and diethyl sulphite. The main product of the reaction, 4,5-diphenylisothiazol-3-ol (17) (47%), is accompanied by a-cyano-a-(4,5-diphenylisothiazol-3-yl)benzyl phenyl thione (18) (up to 15%). The use of other dialkyl sulphites produces the same isothiazolol (17), but in much reduced yields (9—18%). The reaction may possibly proceed by way of the sulphine intermediate (15), as outlined in Scheme 1, terminating with loss of hydrogen cyanide from (16). ... 

Numerous examples of N—S bond formation using oxidative conditions have been described in the literature. A convenient synthesis of isothiazoles involves the direct oxidation of -y-iminothiols and numerous variations have been studied (see Chapter 4.17), The oxidation of the amidine (248) to give the 3-aminoisothiazole (249) illustrates the reaction scheme (65AHC(4)107, 72AHC(14)1), which has been extended to the synthetically useful 5-amino-4-cyano-3-methylisothiazole (251) obtained by oxidation of (250) with hydrogen peroxide (75JHC883). 

One of the best methods of synthesis of isothiazoles is by direct oxidation of y- iminothiols (169) or their tautomers. The reaction is capable of many ramifications and is represented by the general equation shown in Scheme 27. The substituents represent a wide range of groups. Thus, iminothioamides (169 R = NH2) are oxidized to give 3-alkyl-5-aminoisothiazoles (170 = NH2), amidines (169 R = NH2) produce 3-amino compounds,... 

The isothiazole ring was used as a template in Woodward s brilliant total synthesis of colchicine (237 Scheme 42) (72AHC(l4)l). 

Coformycin, 2 -deoxy—see Pentostatin Colchicine synthesis, 1, 472 isothiazoles in, 6, 174 Collins reagent as oxidizing agent, 2, 170 Colour... 

Furoic acids — see Furancarboxylic acids Furo[3,4-d]isothiazole-4,6-dione, dihydrosynthesis, 6, 999 Furo[2,3-d]isoxazoles synthesis, 5, 148 Furo[3,2-d]isoxazoles synthesis, 6, 997 Furo[3,4-d]isoxazoles... 

Isothiazole, 5-acetamido-3-alkyl-nitrosation, 5, 59 6, 148 Isothiazole, 5-acetyl-thiosemicarbazone biological activity, 6, 175 Isothiazole, 4-acetyl-5-amino-3-bromo-synthesis, 6, 166 Isothiazole, 4-acetyl-3-methyl-oxime... 

Beckmann rearrangement, 6, 156 Isothiazole, 3-alkoxy-tautomerism, 6, 145 Isothiazole, alkyl-bromination, 5, 58 Isothiazole, 3-alkyl-5-amino-synthesis, 6, 166 Isothiazole, alkylthio-mass spectra, 6, 142 Isothiazole, amino-azo dyes from, 1, 330 tautomerism, 6, 157 Isothiazole, 3-amino-synthesis, 5, 135 tautomerism, 6, 146 Isothiazole, 4-amino-azo dyes from, 6, 175 diazotization, 6, 158 methylation, 5, 95 quaternization, 6, 158 reactions... 

Isothiazole, 5-amino-4-cyano-3-methyI-synthesis, 5, 135 Isothiazole, 5-amino-3-methyI-reactions... 

Isothiazole, 4-aryl-3-hydroxy-5-mercapto-methylation, 6, 160 synthesis, 6, 166... 

Isothiazole, 3,5-dichloro-4-cyano-synthesis, 6, 166 Isothiazole, dihydro-1,1-dioxide... 

Isothiazole-4,5-dicarboxylic acid, 3-phenyl-dimethyl ester synthesis, S, 150 Isothiazole-5-glyoxylic acid ethyl ester reduction, 6, 156 Isothiazole-4-mercurioacetate reactions, 6, 164 Isothiazole-5-mercurioacetate reactions, 6, 164 Isothiazoles, 6, I3I-I75 acidity, 6, 141 alkylation, 6, 148 aromaticity, S, 32 6, 144-145 basicity, 6, I4I biological activity, 6, 175 boiling points, 6, I43-I44, 144 bond fixation, 6, 145 bond orders, 6, I32-I34 calculated, 6, 133 bromination, S, 58 6, 147 charge densities, 6, 132-134 cycloaddition reactions, 6, 152 desulfurization, S, 75 6, 152 deuteration, S, 70... 

Naphtho[2,3-h]indolizine-6,l 1-dione, 1, 337 Naphthoisocoumarin synthesis, 3, 831, 832 Naphtho[l,2-c]isothiazole, 3-amino-synthesis, 5, 136 2-Naphthol, l-(2-thiazolylazo)-analytical uses, 6, 328 Naphtholactam, 1, 326 Naphtholactone dyes, 1, 326... 

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