6149-07-1

Upstream product

• 2632-13-5 2-Bromo-4'-methoxyacetophenone 
• 6972-05-0 1,1-dimethyl-2-thiourea 
• 534-13-4 N,N-dimethylthiourea 
• 85656-37-7 3-(4-methoxyphenyl)-5,6-dihydrothiazolo<2,3-b>thiazolium bromide 
• 124-40-3 dimethyl amine 
• 100-06-1 1-(4-methoxyphenyl)ethanone 

Downstream Products

• 85656-62-8 4-(4-methoxyphenyl)-2-dimethylaminothiazole-5-carbaldehyde 
• 89563-79-1 2-dimethylamino-4-(4-methoxyphenyl)-5-trifluoroacetylthiazole 
• 89563-61-1 2-dimethylamino-4-(4-methoxyphenyl)-5-nitrothiazole 

Relevant academic research and scientific papers

Electrophilic Substitution at C(5) of 2-Dimethylaminothiazoles

The reactivity of a series of 4-substituted 2-dimethylaminothiazoles towards electrophiles has been examined.Acetic anhydride reacts only slowly with these thiazoles, with trichloroacetyl chloride and trifluoroacetic anhydride substitution at C(5) occurs readily.The rate of trichloroacetylation is influenced, but not to a marked extent, by changing the 4-substituent.In the presence of acid the thiazoles are deuteriated at C(5), and this reaction is much more sensitive to the nature of the 4 substituents.Estimated p Ka values of the thiazoles were used in evaluating rate constants which although only approximate, provide quantitative information about the effect of particular substituents.

2-(N,N-Disubstituted Amino)thiazoles with Electron-withdrawing Groups at Position 5: Prepaeation and Investigation on Structural Features

A convenient procedure for preparing N-mono- and NN-di-substituted cyanamides from cyanogen bromide has been developed.N,N-Disubstituted thioureas, obtained from the cyanamides, were condensed with α-bromo-α-cyanoketones to give 5-cyano-2-(N,N-disubstituted amino)thiazoles and with α-bromo-ketones to give 2-(N,N-disubstituted amino)thiazoles.Substitution in the latter products afforded 5-trifluoroacetyl- and 5-nitro-2-(N,N-disubstituted amino)thiazoles; nitration is greatly facilitated by the presence of a 4-aryl group.The average values of the barriers of rotation of the barriers to rotation of the 2-NR2 groups (ΔG298) in the 5-substituted thiazoles were established by variable temperature 1H n.m.r. spectrometry to be 57.4 kJ mol -1 (5-NO2), 56.2 (5-COCF3), and 51.5 (5-CN).I.r. examination showed that the 5-trifluoroacetyl compounds adopt one rotational form preferentially; this is probably the carbonyl O,S-syn-conformation.

N,N-Disubstituted 2-Aminothiazole-5-carbaldehydes: Preparation and Investigation of Structural Features

Methods of preparing N,N-disubstituted 2-aminothiazoles have been investigated. 4-Substituted N,N-dimethyl-, N-benzyl-N-methyl-, and N-methyl-N-phenyl-amines were prepared and converted by Vilsmeier formylation into 2-amino-5-carbaldehydes which were examined by i.r. and 1H n.m.r. spectrometry.The aldehyde group adopts the carbonyl O,S-syn-conformation.With the N,N-dimethyl and N-benzyl-N-methyl compounds the barrier to rotation of the amine group (ΔG(excit.)) is 50-55 kJ mol-1 and is insensitive to the nature of the 4-substituent.The amine group of the N-methyl-N-phenyl compounds has a marked preference for one orientation.This was shown by a crystallographic study of 4-t-butyl-2-(N-methyl-N-phenylamino)thiazole-5-carbaldehyde to have the phenyl group directed towards the sulphur atom of the thiazole ring.