Infrared 2-methyl-5-substituted derivatives, reaction

Alkylation of A-4-thiazoline-2-one may yield O-R or N-R derivatives according to experimental conditions. With diazomethane in ethanol O-raethylation takes place (29. 36. 214). N-Methylation is reported when a basic solution of A-4-thiazoline-2-one reacts with methyl iodide or dimethylsulfate (21, 29, 215, 216), Reaction of l-chloro-2-dimethyl-aminoethane with the sodium salt of 4 R-A-4-thiazoline-2-one (91) in alcohol, first claimed to yield the aminoalkylether (217, 218), was shown after infrared investigation to give the N-substituted derivative (92) (107), even when R Ph (Scheme 45). More probably the site of reaction in... 

The reaction is specific in that the allyl group retains its configuration in the course of transfer. Thus reactions of metallic mercury with an asymmetrically substituted 7r-allylpalladium chloride (for example, crotyl-palladium chloride) might equally afford both cis- and /raMr-2-butenyl-mercury chloride isomers, as well as the 1-butenyl compound. Hence generally three compounds could be expected in the reaction. However, it has been found 161) that essentially the reaction yields only trans-crotylmercury chloride (based on infrared spectra). In the case of 1-phenyl-77-allylpalladium chloride and l-acetyl-2-methyl-7r-allylpalladium chloride, again only the respective y-substituted /raw-allylmercury halides have been found. Since such conditions do not allow the allyl rearrangement 162), formation of the /ra r-allylmercury derivatives is evidence that the... 

Only 4H-4-OXO derivatives of this heterocycle have been prepared. The infrared spectra of these compounds show a characteristic carbonyl absorption at 1780-1790 cm A variety of 2-methyl compounds have been obtained by reaction of the appropriately substituted aminopyrazinecarboxylic acids (9) with acetic anhydride, " an approach which has been described in many patents.Other anhydrides such as propionic and butyric anhydrides react to give the expected products. No reports of 2-unsubstituted compounds have appeared. 

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