Alkylthio

The thioboration of terminal alkynes with 9-(alkylthio)-9-borabicyclo[3.3.1]-nonanes (9-RS-9-BBN) proceeds regio- and stereoselectively by catalysis of Pd(Ph,P)4 to produce the 9-[(Z)-2-(alkylthio)-l-alkeny)]-9-BBN derivative 667 in high yields. The protonation of the product 667 with MeOH affords the Markownikov adduct 668 of thiol to 1-alkyne. One-pot synthesis of alkenyl sulfide derivatives 669 via the Pd-catalyzed thioboration-cross-coupling sequence is also possible. Another preparative method for alkenyl sulfides is the Pd-catalyzed cross-coupling of 9-alkyl-9-BBN with l-bromo-l-phe-nylthioethene or 2-bromo-l-phenylthio-l-alkene[534]. 

Nuclear magnetic resonance spectra of 2-alkylthio-4-amino-5-R-thiazoles have been recently described (135). 

A-2-Thiazoline-4-ones are usually obtained by the heterocydization method (38b-388). 2 Alkylthio-4(5)-thiazolones (162) are obtained by alkylation at sulfur of rhodanine (160) in nonpolar solvent (Scheme 85). 

Chloro- and 2-alkylthio-4(5)-thiazolone (184) when treated in basic medium yields the corresponding 2.4-thiazolinediones (185) (Scheme 96)... 

The alkylthio group is replaceable by nucleophiles. The positions 7 and 4 react under mild conditions in that order the 2-alkylthio functions require more drastic treatment. Conversion of l-methyl-4-methylthiopteridin-2-one (157) into the 4-methylamino derivative (158) can be achieved by stirring with methylamine at room temperature (equation 48). The reactivity of an alkylthio group can often be further enhanced by oxidation to the corresponding sulfoxide and sulfone. Thus, reaction of l,3-dimethyl-7-methylthiolumazine (160) with m-chloroperbenzoic acid yields 7-methylsulfinyl- (161) and 7-methylsulfonyl-l,3-dimethyllumazine (162 equation 49) (82UP21601). 4-Amino-2-methylthio-7-... 

Benzo[6]thiophene, 2-acetyl-3-hydroxy-synthesis, 4, 892 Benzo[6]thiophene, 2-acyl-synthesis, 4, 918 Benzo[6]thiophene, 3-acyl-synthesis, 4, 918- 19 Benzo[6]thiophene, acylamino-synthesis, 4, 815 Benzo[6]thiophene, alkenyl-synthesis, 4, 917 Benzo[6]thiophene, 2-alkoxy-synthesis, 4, 929 Benzo[6]thiophene, 3-alkoxy-synthesis, 4, 929 Benzo[6]thiophene, 4-alkoxy-synthesis, 4, 930 Benzo[6]thiophene, 2-alkyl-synthesis, 4, 877-878 Benzo[6]thiophene, 2-alkylthio-synthesis, 4, 931 Benzo[6]thiophene, 2-amino-diazotization, 4, 810 reactivity, 4, 797 stability, 4, 810 synthesis, 4, 869, 924-925 tautomerism, 4, 38 Benzo[6]thiophene, 3-amino-cycloaddition reactions, 4, 68 synthesis, 4, 109, 881, 925 Benzo[6]thiophene, 4-amino-synthesis, 4, 925 Benzo[6]thiophene, 5-amino-synthesis, 4, 925 Benzo[6]thiophene, 7-amino-synthesis, 4, 925 Benzo[6]thiophene, 3-t-amyl-synthesis, 4, 915 Benzo[6]thiophene, 2-aryl-synthesis, 4, 881... 

Pyrimidine, I-alkyl-2-methyltetrahydro-C-thioacylation, 4, 807 Pyrimidine, 4-alkylsulfinyl-nucleophilie displaeement reaetions, 3, 97 Pyrimidine, 6-alkylsulfinyl-nucleophilic displacement reactions, 3, 97 Pyrimidine, 2-alkylsulfonyl-nueleophilie displaeement reactions, 3, 97 Pyrimidine, 4-alkylsulfonyl-nucleophilic displacement reactions, 3, 97 Pyrimidine, 6-alkylsulfonyl-nucleophilie displaeement reactions, 3, 97 Pyrimidine, alkylthio-dealkylation, 3, 95 desulfurization, 3, 95 oxidation, 3, 96 synthesis, 3, 135, 136 Pyrimidine, 2-alkylthio-aminolysis, 3, 96 hydrolysis, 3, 95 Prineipal Synthesis, 3, 136 Pyrimidine, 4-alkylthio-aminolysis, 3, 96 hydrolysis, 3, 95 Pyrimidine, 6-alkylthio-aminolysis, 3, 96 hydrolysis, 3, 95 Pyrimidine, 4-allenyloxy-rearrangement, 3, 93 Pyrimidine, 4-allyloxy-2-phenyl-rearrangement, 3, 93 Pyrimidine, 4-allynyloxy-rearrangement, 3, 93 Pyrimidine, 4-anilino-2,5,6-trifluoro-NMR, 3, 63 Pyrimidine, 2-aryl-pyrroleaeetic aeid from, 4, 152 Pyrimidine, arylazo-synthesis, 3, 131 Pyrimidine, 4-arylazo-reduetion, 3, 88... 

Thiazole, 2-acetylamino-4-methyl-alkylation, 6, 256 Thiazole, 2-acylamino-4-hydroxy-synthesis, 6, 297 Thiazole, 5-alkoxy-cleavage, 6, 289 synthesis, 6, 302 Thiazole, 2-alkyl-A7-alkylation, 6, 253 hydrogen exchange, 6, 276 methylation, 6, 253 quatemization, 6, 253-254 reactions, S, 88 Thiazole, 4-alkyl-A7-alkylation, 6, 253 methylation, 6, 253 quatemization, 6, 253-254 Thiazole, 5-alkyl-A7-alkylation, 6, 253 methylation, 6, 253 Thiazole, 2-alkylamino-tautomerism, 6, 248 Thiazole, 4-alkyl-2,5-dimethyl-quatemization, 6, 253-254 Thiazole, 2-alkylthio-reactions, S, 103 rearrangement, 5, 103 6, 291 Thiazole, 3-allyl-4-hydroxy-2-imino-synthesis, 6, 297 Thiazole, 2-allyloxy-rearrangement, 6, 289 Thiazole, 2-amino-diazo coupling, 6, 257 nitration, 6, 255... 

In 1939, the ultraviolet spectrum of 4-methylquinol-2-thione was reported to differ from that of the 2-alkylthio analog, and the former compound was concluded to exist in the thione form. However, other investigators were unable to reach any conclusions from ultraviolet and infrared spectral data concerning the tautomerism of quinol-2- and -4-thione. A definitive pK and ultraviolet spectral investigation by Albert and Barlin has recently established that the thione forms of quinol-2- and -4-thione and of isoquinol-1- and -3-thione (cf. 202) greatly predominate (Table V). The infrared... 

Alkylthio, arylthio, and thioxo. The thioxo group in pyrimidine-2,4-dithione can be displaced by amines, ammonia, and amine acetates, and this amination is specific for the 4-position in pyrimidines and quinazolines. 2-Substitution fails even when a 5-substituent (cf. 134) sterically prevents reaction of a secondary amine at the 4-position. Acid hydrolysis of pyrimidine-2,4-dithione is selective at the 4-position. 2-Amination of 2-thiobarbituric acid and its /S-methyl derivative has been reported. Under more basic conditions, anionization of thioxo compounds decreases the reactivity 2-thiouracil is less reactive toward hot alkali than is the iS-methyl analog. Hydrazine has been reported to replace (95°, 6 hr, 65% 3deld) the 2-thioxo group in 5-hexyl-6-methyl-2-thiouracil. Ortho and para mercapto- or thio- azines are actually in the thione form. ... 

The condensation of 4-diethylaminobut-3-en-2-one with 5-alkylisothiuronim salts proceeds in the presence of catalytic amounts of acids (60-90°C, 1 h) to afford high yields of 2-alkylthio-4-methylpyrimidines (276) (76ZOR2063). 

Athoxycarbonyl- 600 2-(Athoxymethylen-amino)- 351 2-Alkylthio-4,5-dihydro- 347 2-Amino- 351 2-Aminocarbonyl- 600 2-Benzylaminocarbonyl- 600 2-Carboxy- 600... 

Condensation of N-perchloroethenylbenzimidoyl chlorides 13 with S-alkylisothiuronium iodides leads to the formation of 4,6-disubstituted 2-alkylthio-l,3,5-triazines 14 in high yields. Their TV-alkyl isomers 15 are synthesized by successive treatment of chlorides 13 with strong basic primary amines and sodium thiocyanate <99MI996>. 

The synthesis and the antifungal, anti-inflammatory and analgesic effects <2006MI4>, or antimicrobial activity <2006MI5> of novel l-alkyl-2-alkylthio-l,2,4-triazolobenzimidazole derivatives have been communicated. 

From Dialkyl 2-Aminothiocarbonylmalonates, Dialkyl (2-Alkylthio)thiocarbonyl malonates and Their Derivatives... 

From 2-(Aminothiocarbonyl)malonates and [2-(Alkylthio)thiocarbonyl]malonates... 

Meyers and Ford (76JOCI735), and Hirai et al. (72CPB206) have used 2-(alkylthio)-2-oxazolines or thiazolines to prepare the corresponding thi-iranes upon treatment with bases and subsequently with carbonyl compounds. The reactions of 2-pyridyl sulfides are expected to proceed similarly as shown in Scheme 22, since the oxazoline ring is a good leaving group in the intramolecular substitution reaction. When optically active oxazolines are used, asymmetric induction takes place to afford the optically active thiiranes in 19-32% enantiomeric excess (ee). The process is shown in Scheme 23. 

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