- Efficient Method for the Synthesis of Amino-1,3-Oxazines from Thioureas
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The synthesis of a subtype-selective inhibitor BACE-1 inhibitor is presented. One of the key transformations in this sequence is the conversion of a thiourea to the bicyclic 1,3-aminooxazine. This article outlines the development and application of this method to the target molecule as well as further exploration of its scope and mechanism.
- Richardson, Jeffery,Lindsay-Scott, Peter J.,Larichev, Vladimir,Pocock, Emily
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supporting information
p. 2853 - 2863
(2020/12/22)
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- N'-Substituted N-Acyl- and N-Imidoyl-thioureas: Preparation and Conversion of N',N'-Disubstituted Compounds into 2-(N,N-Disubstituted Amino)thiazol-5-yl Ketones
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Known methods were developed to give convenient general procedures for preparing N-acyl-N'-mono- and -N',N'-disubstituted thioureas from acid chlorides, and related N-imidoyl thioureas from imidoyl chlorides.In the products from three acid chlorides and ammonium thiocyanate the acyl isothiocyanates did not appear to be accompained by the isomeric thiocyanates.Treatment of N-(anilino)benzylidene-N',N'-disubstituted thioures with chloroacetone in the presence of triethylamine leads to 5-acetyl-4-phenyl-2-(N,N-disubstituted amino)thiazoles.In contrast, the corresponding N-benzoyl thioureas form only small amounts of these compounds; the main products are the 5-benzoyl-4-methyl isomers, and this unexpected outcome requires a revision of the literature.It is thought that formation of the 5-benzoyl-4-methylthiazoles involves N-C(4) fission of a cyclic intermediate to give an open-chain intermediate in which nucleophilic attack can occur at either the acetyl or the benzoyl group.One of the latter intermediates was generated directly from 2-acetyl-2-bromoacetophenone and N-methyl-N-phenylthiourea, and found to give the 5-benzoyl-4-methyl- and 5-acetyl-4-phenyl-thiazoles as the major and minor products, respectively.
- Brindley, Jocelyn C.,Caldwell, Jennifer M.,Meakins, G. Denis,Plackett, Simon J.,Price, Susan J.
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p. 1153 - 1158
(2007/10/02)
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