Phenyltrimethylammonium Tribromide Research Articles

An efficient route for the synthesis of 2-arylthiazino[5,6- b]indole derivatives

Substituted 2-thiobenzamidomethylindole derivatives ( 14a– e) were prepared by the reaction of 2-aminomethylindole ( 9) with substituted benzoyl chlorides, followed by sulfurization using Lawesson's reagent. Alternatively, these thioamides were obtained from the amine in one step in an efficient manner by using substituted benzaldehydes in the presence of sulfur, or at room temperature with the aid of substituted methyl dithiobenzoates. The Hugerschoff reactions of thiobenzamides ( 14a– e) with phenyltrimethylammonium tribromide provided the rare title 2-arylthiazino[5,6- b]indoles ( 15a– e) in good yields. A convenient one-pot approach for the synthesis of 2-phenyl-1,3-thiazino[5,6- b]indole ( 15a) from 2-aminomethylindole ( 9) is also described.

Metal porphyrin/phenyltrimethylammonium tribromide: High efficient catalysts for coupling reaction of CO 2 and epoxides

Novel and high efficient catalysts of metal porphyrin (M(TPP)X, M = Co, Fe, Ru, Mn; X = Cl −, Br −, OAc −, OTs −, Cl 3CCO 2 −)/phenyltrimethylammonium tribromide (PTAT) were developed to catalyze the coupling reaction of carbon dioxide and epoxides at room temperature.

Three-Step Synthesis of Highly Substituted Phenols from 1,3-Dinitropropanes

Reaction of 1,3-dinitropropanes with acrolein under heterogeneous conditions (neat Al2O3) gives dinitrocyclohexanols, which, by treatment with potassium carbonate followed by acidic work-up, allow access to nitrocyclohexenone derivatives. The latter, by reaction with phenyltrimethylammonium tribromide, concludes a three-step synthesis of nitro-dibromophenols in satisfactory yields.

Chemoselective conversion of aromatic epoxide and 1,2-diol to 1,3-dioxane derivatives with phenyltrimethylammonium tribromide in the presence of a catalytic amount of antimony(III) bromide

trans-Stilbene oxide was oxidatively converted to 2-phenyl-1,3-dioxanes with phenyltrimethylammonium tribromide in the presence of various 1,3-diols and a catalytic amount of SbBr 3 in DMSO at room temperature. Aromatic 1,2-diol, such as hydrobenzoin, was similarly converted to 2-aryl-1,3-dioxane derivatives under the same reaction conditions.

Synthesis of thiazino[6,5- b]indole derivatives, analogues of the phytoalexin cyclobrassinin. A new method for preparation of 3-aminomethylindole

An efficient non-reductive synthesis of 3-aminomethylindole ( 6 ) was developed from gramine ( 1 ) via 3-phthalimidomethylindole ( 2 ). The reactions of amine 6 with substituted methyl dithiobenzoates gave 3-(arylthiocarbonylaminomethyl)indoles. The Hugerschoff ring-closure reactions of the thiobenzamide intermediates ( 11a– f ) with phenyltrimethylammonium tribromide and subsequent basic treatment furnished 2-arylthiazino[6,5- b]indole derivatives ( 14a– f ). By use of the latter bromine source, the phytoalexin cyclobrassinin ( 8 ) was prepared in a considerably higher yield than described previously. The structures of the novel products were elucidated by IR, 1H and 13C NMR spectroscopy, including 2D-HMQC, 2D-HMBC and DEPT measurements.

Oxidation of Secondary Alcohols with Phenyltrimethylammonium Tribromide in the Presence of a Catalytic Amount of Antimony(III) Bromide or Copper(II) Bromide.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Hantzsch reaction of 3‐(2‐bromoacetyl)‐4‐hydroxy‐chromen‐2‐one. Synthesis of 3‐(thiazol‐4‐yl)‐4‐hydroxy coumarines

Abstract3‐Acetyl‐4‐hydroxy‐chromen‐2‐one (1) was brominated with phenyltrimethylammonium tribromide to afford 3‐(2‐bromoacetyl)‐4‐hydroxy‐chromen‐2‐one (2) whose reactions with thiourea, thioacetamide and ammonium dithiocarbamate gave respectively 3‐(2‐amino‐thiazol‐4‐yl)‐4‐hydroxy‐, 4‐hydroxy‐3‐(2‐phenyl‐thiazol‐4‐yl)‐ and 4‐hydroxy‐3‐(2‐mercapto‐thiazol‐4‐yl)chromen‐2‐one. In a similar manner, com pound 2 was treated with four 1‐substituted‐2‐thioureas and thiobenzamide to give the corresponding 4‐hydroxy‐3‐(thiazol‐4‐yl)‐chromen‐2‐one derivatives.

Oxidation of Secondary Alcohols with Phenyltrimethylammonium Tribromide in the Presence of a Catalytic Amount of Antimony(III) Bromide or Copper(II) Bromide

The oxidation of alcohols was carried out with phenyltrimethylammonium tribromide in the presence of a catalytic amount of SbBr 3 or CuBr 2 . 1,2-Diols, such as hydrobenzoin, were converted into 1,2-diketones or α-ketols without oxidative cleavage of the glycol C-C bond at room temperature. A variety of secondary alcohols were also oxidized to the corresponding carbonyl compounds in a chemoselective manner.

Synthesis of some 3-(thiazol- 4-yl)-4-hydroxy coumarines

In this work, an easy and efficient procedure for the synthesis of eight 3-(thiazol-4-yl)-4-hydroxychromen-2-one derivatives is presented. 3-Acetyl-4-hydroxychromen-2-one (1) was brominated with phenyltrimethylammonium tribromide to afford 3-(2-bromoacetyl)-4-hydroxychromen-2-one (2). Compound 2 reacts with thiourea, thioacetamide and ammonium dithiocarbamate to afford 3-(2-aminothiazol-4-yl)-4-hydroxychromen-2-one (3), 4-hydroxy-3-(2-methylthiazol-4-yl)chromen-2-one (4a) and -1-hydroxy-3-(2-mercaptothiazol-4-yl)chromen-2-one (5), respectively. In a similar manner, compound 2 was treated with four mono-N-substituted thioureas and thiobenzamide to give the corresponding 3-(thiazol-4-yl)-4-hydroxychromen-2-one derivatives.

Synthesis of Biologically Important New 1,4‐Benzothiazines Bearing Thiazole Substituted Aroyl Moiety.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis and Antimicrobial Activities of New 1,4‐Benzothiazines Possessing Thiazolyl/Imidazolyl Moieties.

3-[4'-Methyl-2'-(4'-substituted-phenyl)thiazol-5'-yl]-1,4-benzothiazine hydrobromides (3A) and 3-[1'-(4-substituted-phenyl)-2'-mercapto-4'-imidazol-5'-yl]-1,4-benzothiazine hydrobromides (3B) were synthesized. 5-Acyl-4-methylthiazoles (1A) and 5-acyl-2-mercapto-4-methylimidazoles (1B) were brominated using phenyltrimethylammonium tribromide as selective brominating agent to obtain the corresponding bromoacyl products 2A and 2B. These bromoacyl products when cyclocondensed by refluxing with 2-aminobenzenethiol in alcohol yielded the title compounds 3A and 3B. They were screened against microorganisms.

Multi‐Step Synthesis of Benzopyranones (VI) via a Key Step Involving Reaction of the Intermediate Compound (IV) with Phenyltrimethylammonium Tribromide.

Multi‐Step Synthesis of Benzopyranones (VI) via a Key Step Involving Reaction of the Intermediate Compound (IV) with Phenyltrimethylammonium Tribromide.

Multi‐step synthesis of benzopyranones via a key step involving reaction of the intermediate compound with phenyltrimethylammonium tribromide

AbstractBase catalysed condensation of a substituted 2‐hydroxyacetophenone with acetic anhydride and sodium acetate followed by cyclization of the intermediate with acid gave substituted 3‐acetyl‐2‐methyl‐4H‐1‐benzopyran‐4‐ones. These were then brominated with phenyltrimethylammonium tribromide (PTT) to yield the desired 3‐(2‐bromoacetyl)benzopyran‐4‐ones. The latter compound on treatment with primary and secondary aryl or alkyl amines, gave the corresponding benzopyran‐4‐one derivatives.

Kinetics of bromination of substituted acetophenones by phenyltrimethylammonium tribromide

Kinetics of bromination of substituted acetophenones by phenyltrimethylammonium tribromide

Intramolecular bromine-catalyzed aziridination: a new direct access to cyclic sulfonamides

N-Chloramine salts of ω-unsaturated sulfonamides have been prepared and shown to react in an intramolecular fashion in the presence of a catalytic amount of phenyltrimethylammonium tribromide to yield bicyclic aziridines. This intramolecular bromine-catalyzed aziridination procedure gave results complementary to those obtained by the copper-catalyzed methodology based on iminophenyliodinane.

Synthesis and reactions of large-ring spiro-dienone calixarene derivatives

Abstract

Synthesis of 3‐(dibromoacetyl)tropolone and its reactions with thioureas and thioamides

Abstract3‐(Dibromoacetyl)tropolone (3) was obtained in the reaction of 3‐acetyltropolone with two equimolar amounts of phenyltrimethylammonium tribromide. This tropolone 3 reacted with thiourea, 1‐methyl‐2‐thiourea, and 1‐phenyl‐2‐thiourea to afford N‐unsubstituted and N‐methyl‐ or N‐phenyl‐substituted 3‐(2‐amino‐4‐thiazolyl)tropolones. The reactions of 3 with thioacetamide and thiobenzamide gave 3‐(2‐methyl‐and 2‐phenyl‐4‐thiazolyl)tropolones.

ChemInform Abstract: Phenyltrimethylammonium Tribromide for Selective Oxidation of Sulfides to Sulfoxides. A Convenient Synthesis of Sulfinyl‐18O‐Labelled Sulfoxide Carboxylic Acids.

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Phenyltrimethylammonium Tribromide for Selective Oxidation of Sulfides to Sulfoxides. A Convenient Synthesis of Sulfinyl-18O-Labelled Sulfoxide Carboxylic Acids

Various sulfides can be oxidized selectively to the corresponding sulfoxides in high yields using phenyltrimethylammonium tribromide in aqueous pyridine solution. This method allows 18 O-labelled sulfoxides to be prepared with no loss of isotope enrichment of the ( 18 O)water used.

ChemInform Abstract: Hantzsch Reaction of 3‐(2‐Bromoacetyl)tropolone. Synthesis of 3‐(4‐Thiazolyl)tropolones.

3-Acetyltropolone was brominated with phenyltrimethylammonium tribromide to afford 3-(2-bromoacetyl)-tropolone (2), whose reactions with thiourea, thioformamide, and ammonium dithiocarbamate gave respectively 3-(2-amino-4-thiazolyl)-, 3-(4-thiazolyl)-, and 3-(2-mercapto-4-thiazolyl)tropolone. In a similar manner, compound 2 was treated with six 1-substituted 2-thioureas and three thioamides to give the corresponding 3-(4-thiazolyl)tropolone derivatives.