- Process for the preparation of substituted thiazolines and their intermediates
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Process for the preparation of substituted thiazolines of the formula (I) 1in which Ar is a phenyl, naphthyl, thienyl, pyridyl or quinolinyl radical which can optionally be substituted by one or more substituents from the group consisting of halogen, OH, benzyloxy, C1-C4-alkyl, C1-C4-alkoxy, COOR1 where R1 is H or C1-C4-alkyl, by coupling of (S)-α-methylcysteine hydrochloride of the formula (II) 2with a nitrile of the formula (III) Ar—CN in which Ar is as defined above, or a corresponding C1-C4-alkyl imidate, in which (S)-a-methylcysteine hydrochloride of the formula (II) is reacted in a suitable solvent with a nitrile of the formula (III) or a corresponding C1-C4-alkyl imidate in the presence of a tertiary base at a pH of 6.5 to 10 at 50° C. up to the reflux temperature to give the corresponding thiazoline of the formula (I), and processes for the preparation of (S)-α-methylcysteine hydrochloride and its use for the preparation of thiazolines of the formula (I).
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- Natural Products as Pesticides: Two Examples of Stereoselective Synthesis
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The strategy and synthetic efforts leading to efficient stereoselective syntheses of thiangazole, a tris-thiazolinyl-oxazole metabolite isolated from Polyangium spp., and hydantocidin, a spironucleoside metabolite isolated from Streptomyces hygroscopicus, are discussed.
- Frueh, Thomas,Chemla, Philippe,Ehrler, Juerg,Farooq, Saleem
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