Reactions of 1-Phenyl-1,2,3-triazolyllithium Compounds; Formation of Ketenimines, Alkynylamines, and Heterocycles from the Ambident (N-Phenyl)phenylketenimine Anion

1971 ◽  
Vol 49 (11) ◽  
pp. 1792-1798 ◽  
Author(s):  
R. Raap
Keyword(s):  
Methyl Iodide ◽  
Heterocyclic Compound ◽  
Room Temperature ◽  
Dimethyl Sulfate ◽  
Phenyl Isocyanate ◽  
Ambident Anion ◽  
Membered Heterocyclic Compound

At room temperature 1,4-diphenyl-1,2,3-triazolyllithium rapidly undergoes fragmentation to nitrogen and lithium (N-phenyl)phenylketenimine anion 8c, [Formula: see text]. Some of the reactions of this ambident anion have been studied. Reaction of 8c with methyl iodide results in C-methylation to a mixture of (N-phenyl)methylphenylketenimine and 3-methyl-1,3-diphenyl-4-(2′-phenylethylene)-2-phenyliminoazetidine. A six-membered heterocyclic compound, 6-anilino-1,3,5-triphenyluracil, results from the reaction between 8c and phenyl isocyanate. With dimethyl sulfate and methyl chloroformate N-alkylation and N-acylation takes place predominantly, forming N-methyl-N-phenyl-2-phenylethynylamine and N-carbomethoxy-N-phenyl-2-phenylethynylamine respectively. Reaction of 8c with methanol and ethanethiol gives an iminoester and an iminothioester respectively.1-Phenyl-1,2,3-triazolyllithium and 4-methyl-1-phenyl-1,2,3-triazolyllithium undergo fragmentation at somewhat higher temperatures.

scholarly journals The Synthesis and Reactions of Chiral Sulfonium Ylids

1974 ◽  
Vol 52 (16) ◽  
pp. 2953-2959 ◽  
Author(s):  
Stewart J. Campbell ◽  
D. Darwish
Keyword(s):  
Acetic Anhydride ◽  
Room Temperature ◽  
Dimethyl Sulfate ◽  
Phenyl Isocyanate ◽  
Methyl Sulfate ◽  
Pyramidal Inversion ◽  
Benzoic Anhydride

Treatment of (−)-ethylmethylsulfonium phenacylid, (−)-1, in THF at room temperature with 15 equiv. of benzoic anhydride, acetic anhydride or 1 equiv. phenyl isocyanate produces the corresponding (−)-ethylmethylsulfonium diacylmethylids, (−)-5, (−)-6, and (−)-8. Treatment of (−)-1 with dimethyl sulfate in acetone gives (Z)-(+)-ethylmethyl-α-methoxy-β-styrylsulfonium methyl sulfate, (+)-10. Resolution of (±)-10 via its DBT salt and conversion to perchlorate gives the corresponding vinyl perchlorates (+)- and (−)-13. Under the resolution conditions the ketal perchlorates, (−)- and (+)-ethylmethyl-2,2-dimethoxy-2-phenylethylsulfonium perchlorate, (−)- and (+)-14, are also obtained. The rates of racemization at 50° in benzene of 1, 5, 6, and 8 are 39.7, 55.5, 106, and 79.1 × 10−5 s−1 respectively. The rates of racemization at 50° in methanol of 10, 13, and 14 are 1.93, 2.08, and 5.64 × 10−5 s−1. Racemization is proposed to proceed via pyramidal inversion. The synthetic potential of chiral sulfonium ylids is discussed with respect to their ease of racemization.

New Potential Biologically Active Compounds: Synthesis and Characterization of Urea and Thiourea Derivativpes Bearing 1,2,4-oxadiazole Ring

2020 ◽  
Vol 17 (7) ◽  
pp. 525-534 ◽  
Author(s):  
Nevin Arıkan Ölmez ◽  
Faryal Waseer
Keyword(s):  
Microwave Irradiation ◽  
Room Temperature ◽  
Antimicrobial Activities ◽  
Phenyl Isocyanate ◽  
Single Step ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Active Compounds ◽  
Thiourea Derivatives ◽  
Acyl Chlorides

Background: Urea, thiourea, and 1,2,4-oxadiazole compounds are of great interest due to their different activities such as anti-inflammatory, antiviral, analgesic, fungicidal, herbicidal, diuretic, antihelminthic and antitumor along with antimicrobial activities. Objective: In this work, we provide a new series of potential biologically active compounds containing both 1,2,4-oxadiazole and urea/thiouprea moiety. Materials and Methods: Firstly, 5-chloromethyl-3-aryl-1,2,4-oxadiazoles (3a-j) were synthesized from the reaction of different substituted amidoximes (2a-j) and chloroacetyl chloride in the presence of pyridine by conventional and microwave-assisted methods. In the conventional method, 1,2,4-oxadiazoles were obtained in two steps. O-acylamidoximes obtained in the first step at room temperature were heated in toluene for an average of one hour to obtain 1,2,4-oxadiazoles. The yields varied from 70 to 96 %. 1,2,4-oxadiazoles were obtained under microwave irradiation in a single step in a 90-98 % yield at 160 °C in five minutes. 5-aminomethyl-3-aryl-1,2,4- oxadiazoles (5a-j) were obtained by Gabriel amine synthesis in two steps from corresponding 5-chloromethyl-3- aryl-1,2,4-oxadiazoles. Finally, twenty new urea (6a-j) and thiourea (7a-j) compounds bearing oxadiazole ring were synthesized by reacting 5-aminomethyl-3-aryl-1,2,4-oxadiazoles with phenyl isocyanate and isothiocyanate in tetrahydrofuran (THF) at room temperature with average yields (40-70%). Results and Discussions: An efficient and rapid method for the synthesis of 1,2,4-oxadiazoles from the reaction of amidoximes and acyl halides without using any coupling reagent under microwave irradiation has been developed, and twenty new urea/thiourea compounds bearing 1,2,4-oxadiazole ring have been synthesized and characterized. Conclusion: We have synthesized a new series of urea/thiourea derivatives bearing 1,2,4-oxadiazole ring. Also facile synthesis of 3,5-disubstituted 1,2,4-oxadiazoles from amidoximes and acyl chlorides under microwave irradiation was reported. The compounds were characterized using FTIR, 1H NMR, 13C NMR, and elemental analysis techniques.

Sulfur Linkage in Vulcanized Rubber. Reaction of Methyl Iodide with Sulfur Compounds

1949 ◽  
Vol 22 (1) ◽  
pp. 1-7
Author(s):  
M. L. Selker
Keyword(s):  
Methyl Iodide ◽  
Room Temperature ◽  
Sulfur Compounds ◽  
Point Of View ◽  
Secondary Reaction ◽  
Reaction Products ◽  
Sulfide Sulfur ◽  
Vulcanized Rubber ◽  
Allyl Sulfide

Abstract The work described here is an extension of the study of the reaction of methyl iodide with sulfur compounds originally begun with the purpose of using such data in determining the sulfur linkage in vulcanized rubber. A previous paper dealt with the reactions of methyl iodide with propanethiol, propyl sulfide, propyl disulfide, allyl sulfide, and thiophene. This article adds to the list, n-butyl methallyl sulfide, allyl disulfide, allyl tetrasulfide, n-propyl tetrasulfide, and trithiane. The removal of combined sulfur from vulcanized rubber as trimethylsulfonium iodide on treatment with methyl iodide at room temperature was persuasive evidence of the presence of sulfide sulfur linked to allylic type residues. The evidence offered, however, did not constitute exclusive proof because it was not known whether still other types of sulfur linkage would also yield trimethylsulfonium iodide. To shed more light on this question, the sulfur linkages most likely to occur in vulcanizates—the allyl-alkyl monosulfide, diallyl and dialkyl di- and polysulfide—were investigated. The trithiane reaction is of interest mostly from the point of view of the reaction of overcured stocks or secondary reaction products stemming from the original polysulfides. The reactions were carried out using the method described in a previous paper.

N-Methylamino acids in peptide synthesis. V. The synthesis of N-tert-butyloxycarbonyl, N-methylamino acids by N-methylation

1977 ◽  
Vol 55 (5) ◽  
pp. 906-910 ◽  
Author(s):  
S. T. Cheung ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Room Temperature ◽  
Sodium Hydride ◽  
Amino Acid Derivatives ◽  
Enantiomerically Pure ◽  
Neutral Amino Acids ◽  
Related Data

The preparation of enantiomerically pure N-tert-butyloxycarbonyl,N-methylamino acids by N-methylation of the parent amino acid derivatives using sodium hydride and methyl iodide in tetrahydrofuran at room temperature is described for neutral amino acids including O-benzyl-protected threonine and tyrosine. Methylation of the O-benzylserine derivative under these conditions gives the N-methyldehydroalanine derivative. The β-elimination is completely suppressed, giving the corresponding N-methylserine derivative when the reaction is carried out at 5 °C. Other related data on N-methylation and N-methylamino acid derivatives are presented.

Local mode assignments for the CD-stretching overtone spectra of deuterated methyl iodide and deuterated methyl cyanide: effects of increased interoscillator coupling on local mode states of C3v symmetry

1988 ◽  
Vol 66 (4) ◽  
pp. 628-632
Author(s):  
M. Khalique Ahmed ◽  
Bryan R. Henry
Keyword(s):  
Liquid Phase ◽  
Methyl Iodide ◽  
Room Temperature ◽  
Local Mode ◽  
Methyl Cyanide

The overtone spectra of CD3I and CD3CN are measured at room temperature in the liquid phase in the regions of CD-stretching local mode overtones corresponding to ΔvCD = 2–5. The spectra are analyzed in terms of a harmonically coupled local mode model. The local mode parameters ω, ωx, and γ′v, the interoscillator coupling between the methyl CD bonds, are determined. A comparison of the spectra of the CH3Z molecules (Z = Cl, Br, I, CN) to the spectra of CD3I and CD3CN reveals the spectral effects of increased interoscillator coupling between the CD bonds.

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