S-Allyl N-acylmonothiocarbamates react in boiling benzene with primary and secondary amines in the presence of catalytic amounts of triethylamine. In this reaction, the S-allyl group is replaced with the amino group under formation of N-acylurea derivatives in 45 - 90% yields. The wide applicability of the reaction is demonstrated by the synthesis of eighty four N-acyl-N'-substituted and N-acyl-N',N'-disubstituted ureas with various aliphatic, aromatic and heterocyclo substituents.
The presence of intramolecular NH...O=C bonds was proved in N-substituted N'-(2-fluorobenzoyl)thiourea derivatives by analysis of their infrared spectra. The intramolecular vibrational effects bring about a shift of the ν(NH) vibrational band to lower frequencies to the extent that the band gets into a vicinity to the δ(NH) overtone and Fermi resonance occurs between them. In addition, the ν(NH) vibration is also affected by Fermi resonance with the ν(CO) + δ(NH) combination. Double absorption bands were observed in the ν(CO) region for some of the derivatives. Based on perturbation theory applied to three-level interactions and using the Langseth and Lord equations, the band frequencies corrected for Fermi resonance were calculated and the hydrogen bond strength was examined in the compounds studied.
2-Chloronicotinoyl isoselenocyanate (IIa) and 2,6-dimethyl-4-chloronicotinoyl isoselenocyanate (IIb) react with arylamines to give 2-arylimino-4-oxopyrido[3,2-e]-1,3-selenazines IV and 2-arylimino-5,7-dimethyl-4-oxopyrido[3,4-e]-1,3-selenazines V. A reaction of IIa,b with sodium hydrogen sulfide and hydroselenide afford the respective 2-thio- and 2-seleno-4-oxopyrido-1,3-selenazines VI and VII. Structure of these new types of heterocycles was corroborated by spectral (IR, UV, 1H NMR, 13C NMR, and mass) means.
Reaction of acetyl, benzoyl, 2-chlorobenzoyl, 3-phenylpropenoyl, 2-naphthoyl, and 3-chloro-2--benzo [b]thienocarbonyl isothiocyanate with 2-propen-l-ol afforded the corresponding 0-(2--propenyl) N-acylmonothiocarbamates which underwent [3,3]-sigmatropic rearrangement on heating in boiling benzene. The reaction represents a simple method for preparation of S-(2--propenyl) N-acylmonothiocarbamates in yields ranging from 50% to 98%.[3,3]-Sigmatropic reactions of 1,5-hexadiene derivatives, the so-called Cope rearrangement l -4 , are recently intensively studied because products obtained in this way are often more easily accessible than by other methods. Reactions of this type have been thoroughly reviewed by Lutz 5 . From the synthetic point of view, compounds containing hetero atoms in positions 1 and 3 are of particular interest. Finding suitable conditions for the [3,3]-sigmatropic rearrangement made it possible to change the kind of substitution or to exchange the functional groups as illustrated by reactions of S-(2-propenyl) dithiocarbamates 6 and the corresponding oxa 7 , aza 8 ,9 or thiaza analogues lO . Only little attention has been paid to compounds containing atoms of oxygen or sulfur in positions 1 and 3 of the 1,5-hexadiene system. O-(2-Propenyl) N,N-dimethylmonothiocarbamates with variously substituted 2--propenyl residues rearrange to the corresponding S-(2-propenyl) esters on heating to 130-140°C (or in some cases spontaneouslyll) without solvent or at room temperature under catalysis with mercuric triftuoroacetate 12 • Recently, a [3,3]-sjgmatropic rearrangement of S-methyl-O-( cx-pinenyI) dithiocarbonate, induced by heating in dimethyl sulfoxide or on silica gel surface, has been reported 13 .In this paper we focussed our attention on the preparation of S-(2-propenyl) N-acylmonothiocarbamates II (Scheme 1) by [3,3]-sigmatropic rearrangement of O-(2-propenyl) N-acylmonothiocarbamates I. Compared with other methods, this approach to compounds of the type II is much simpler. The desired S-(2-propenyl) esters II could be prepared by addition of 2-propene-1-thiol to the corresponding acyl isocyanates; this method has been hitherto used only in the preparation of
The synthesis of 1,3-thiazines, 2-thiouracils and ureas from N-substituted phenyl-N’-(2-methyl-3-phenylpropenoyl)thioureas by intramolecular cyclization or oxidation under various conditions is described. The structure of products was verified by IR, 1H NMR and mass spectral evidence.
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