Thio-amides

Fusion of an additional heterocyclic ring onto that already present in the benzodiazepines has led to some medicinal agents with considerable activity. Treatment of an intermediate like 15 with phosphorus pentasulfide affords the corresponding thio-amide (37). Condensation of this intermediate with acetyl hydra-zide affords triazolam )37). The same agent can be prepared by reaction of the amidine, 38, ° with acetylhydrazide. ... 

Fusion of an additional heterocyclic ring onto a benzodiazepine is well known to considerably increase potency. This increase in potency is apparently maintained when the benzene ring is replaced by thiophene. Thiophene aminoketone 161 is converted to the benzodiazepine analogue 164 via chloroacetamide 162 and then glycine derivative 163 by the same sequence as that used in the benzene series. Treatment of the product 164 with phosphorus pentasulfide gives the thio-amide 165 reaction of that intermediate with hydrazine leads to the amino amidine 166. Conden-... 

Thioacylation of primary and secondary amines, including aminoacids and aminoalcohols, has been readily carried out from phosphonodithioacetate 28 (R = Et) and the resulting phosphorylated thio amides (thio carbamoyl-... 

The course of the alkylation of several potentially tautomeric phosphorus thio amides has been investigated. That of the diphosphazane (238) in the presence of triethylamine... 

A novel and convenient one-pot synthesis of iV-mono-and Nfl -disubstituted thio-amides mediated by A -trifluoromethylsulfonylbenzotriazole is described in reference [167]. 

Diphenylcyclopropene thione also reacts with Schiff bases 379 via the tautomeric vinylamine form to give betaines 380, which tautomerize to the bicyclic thio amides 3 /247 ... 

Wallis185 examined reactions of dimethyl 2-hexen-4-ynedioate with thioureas and thio-amides and observed addition at C-5 via the sulfur atom of these nucleophiles the adducts often cyclize spontaneously to iminothiazolidinones (equation 80). 

But the more heteroatoms, the more alternatives. We could disconnect the enamine first 27a and the C-S bond second 31. This suggests a reasonable a-halo-ketone 33 and an unstable-looking imine 32. Fortunately this is just a tautomer of the thioamide 34. Though thioketones are unstable, thio-amides are stable thanks to extra conjugation. 

Selected Barriers to Rotation around the C—N Bond in Heterocyclic (Thio)amides without an Ortho Steric Effect... 

Butansdure 2-(2-Amino-4-methyl-pentanoylamino)-3-methy]thio- -amid (Hydroacetat) XV/1, 728... 

Method B Action of hydroxylamine on amides or thio amides... 

The thermal dimerisation 110 -> 111 appears to be reversible in solution and reaction of compound 111 with phenyl thioisocyanate in hot THF gives the thio-amide 114 (80LA1952). 

Table 1.1 shows a selection of catalysts developed in 2006-2007, which operate under biphasic aqueous conditions. For previous literature, readers are directed to an excellent review by List and co-workers.In terms of catalyst performance, since 2006 most of the best achievements have been reported for (9-modified Z/Y///A-4-hydroxy-i -prolinc derivatives 3-5, including the inclusion complex 6 of a proline derivative and a P-cyclodextrin, or catalysts consisting of chiral amines 7 and 8 or (thio)amides 9-14 derived from L-proline. The O-protected serine 15a, threonine 15b and threonine amide 16 complete the list of catalysts. 

In early 1997, de Oliveira and his group (89) reported an approach to the tetracyclic core of cephalotaxine that essentially mimicked the earlier chemistry reported by Danishefsky (33) (see Scheme 9, Section III). The thio amides 311 and 312 (Scheme 54) were prepared by alkylation of succinimide with the corresponding )3-piperonyl bromide prepared in two steps from safrole, then functionalized further to the nitrile or ester by chloromethylation, followed by displacement and/or hydrolysis and esterification. The base-catalyzed closure produced the tetracyclic ring systems 313 and 97 in 75 and 22% yield, respectively. These compounds were thus... 

Under basic condition (pH 7.8), this chromophore reacts with oxygen to produce a dioxetanone intermediate. The dioxetanone collapses to alpha-thio-amide with producing blue light (470 nm) and CO2. After the oxidized chromophore decomposes to a coelenteramine, the free active site cysteine becomes available again. 

Finally, 8 reacts with isocyanates (94CM1419) and isothiocyanates (93CC1701 93MI17 94CM1419) to give the corresponding amides and thio-amides (Scheme 54). 4-(jV-Methylthioamido)tetrathiafulvalene is the first example of a neutral tetrathiafulvalene derivative to form a K-phase structure (93CC1701). 

Elemental sulfur and morpholine, reagents of the Willgerodt-Kindler reaction [36], react at room temperature with captodative methylene compounds to form thio-amides with an electron-withdrawing substituent. For example, a-morpholinoketone 54 leads to thioamide 55 [37]. 

Te-O bonds, 453 Te-P bonds, 454 Te-S bonds, 453 Te-Sb bonds, 456 Te-Se bonds, 453 Te-Te bonds, 454 Tellurium cations, 938-942 anions, 1349 cations, 1346-1349 Th-contaming species neutrals, 643-650 Th clusters, 650-651 Thiazyl compounds NSR N-S bonds, 420 -421 Thio-acid RC(0)SH S-C bonds, 438 S-H bonds, 438 Thio-aldehydes RC(S)H C-H bonds, 125 Thio-amides RC(S)NR2 ... 

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