Thioimidate

The thioimidates obtained from peifluorinated nitnles and methylmercaptan can be transformed into thiohydroxyimidates on treatment with hydroxylamine [64] CH-acidic compounds, such as methylketones [63, 66], nitroalkanes [67], and enamines [d jradd to peifluorinated nitnles in the same way (equation 6). 

Cyclization of C2-Blocked N-(Pyrimidin-3-yl)thioimidates with One-Nitrogen Fragments... 

Photolysis of the 2-methyl-quinazolin-3-yl thioimidate 19 in the presence of butylamine produced an intricate mixture of products from which the... 

Entry 6 is analogous to a silyl ketene acetal rearrangement. The reactant in this case is an imide. Entry 7 is an example of PdCl2-catalyzed imidate rearrangement. Entry 8 is an example of an azonia-Cope rearrangement, with the monocylic intermediate then undergoing an intramolecular Mannich condensation. (See Section 2.2.1 for a discussion of the Mannich reaction). Entry 9 shows a thioimidate rearrangement. 

Feldman and Skoumbourdis have utilized an oxidative hydrolysis of the thioimidate with ceric ammonium nitrate (CAN) to generate dibromophakellstatin 78 as the final step in their synthetic sequence (Equation 14) <20050L929>. 

Phosphorus pentachloride, for conversion of pentaacetylgluconic add to add chloride, 41, 80 for oxidation of cycloheptatriene to tropylium fluoborate, 43, 101 with cyanoacetic acid, 41, 5 Phosphorus tribromide, reaction with l,5-hexadien-3-ol, 41, 50 Phthalic acids from thioimides, 44, 93 Phthalic anhydride, reaction with L-phenylalanine to yield N-phthaiyi-L-phenylalanine, 40, 82 Phthalic monoperacid, 42, 77 Phthaionic acid, 44, 63 N-Phthalyl-L-alanine, 40, 84 N-Phthalyl-0-alanine, 40, 84 N-Phthalylglydne, 40,84 N-Phthalyl-l-/3-phenylalanine, 40,82 PlMELIC ACID, (S-OXO-, DIETHYL ESTER, 42,41... 

The thioimides can be hydrolyzed to the corresponding di-carboxylic acids. The thioimides can be converted to the corresponding imides, and thiohomophthalimides can be converted to phthalimides both conversions are one-step processes.4 Thus a variety of substituted phthalic and homophthalic acids and their derivatives are available from these thioimides. 

Glycosyl Thioimidates - Preparation and Application as Glycosyl Donors... 

Scheme 4.86 Orthogonal thioimidate-based, one-pot oligosaccharide synthesis [468].

Reaction of glycosyl thioimidate 79 with aa -dibromo-m-xylene in the presence of NaH as a base and 15-crown-5 as a supporting reagent allowed the intermediate 80 (Scheme 4.88). Treatment of the diol 81 with dibutyltin oxide in dry toluene and then reaction with 80 in the presence of tetrabutylammonium iodide afforded the desired O-linked intermediate 82. Activation of this compound with NIS-TMSOTf afforded 83 in a good yield. Hydrogenolysis followed by acetylation gave the desired disac-... 

In an attempt to understand further the carcinogenicity of azathioprine, recent work in the authors laboratory has concentrated on the photodegradation of two compounds associated with the drug. l-Methyl-4-nitro-5-thioimid-azole is a metabolite and 5-hydroxy- l-methyl-4-nitroimidazole a hydrolysis product. Both gave, on irradiation at wavelengths greater than 300 nm, 1-methylparabanic acid (248) [152], The primary metabolites of azathioprine had previously been shown to be more potent than the parent drug as photosensitizers. Both 6-mercaptopurine and these imidazoles may play roles in its neoplastic action [151]. 

A thioimidate substructure was reported to react analogously with good yields [579]. 

Both saturated or unsaturated thioimides and dithioimides behave like thioketones in their photocycloaddition reaction with alkenes (equation 129) and alkynes (equation 130)185. 

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