N,N-Diethylbenzamide

Efficient Swern oxidation and Corey–Kim oxidation with ion-supported methyl sulfoxides and methyl sulfides

Derivatization of alcohols using acridone-9- N-acetyl-benzene-disulfonate as a condensation agent and its application for the determination of volatile alcohols in human plasma by liquid chromatography with fluorescence detection

Selenium‐Containing Heterocycles From Isoselenocyanates: Synthesis of1,3‐Selenazolidine and Perhydro‐1,3‐selenazine Derivatives

A series of novel functionalized azetidinones containing the benzotriazole moiety were synthesized stereoselectively by a ­reaction of benzotriazolylacetic acid, aromatic amines, and ­Mukaiyama’s reagent in the presence of triethylamine in dichloromethane at ambient temperature. This transformation generates a four-membered lactam and presumably proceeds via in situ generation of benzotriazolylketene as a heteroarylketene. In contrast to the products obtained from the reaction of pyrrolylketene with imines in which cis -azetidinones were formed as major products, the generated benzotriazolylyketene reacted with imines forming the trans -lactams as major products.

3-(7-Methoxycoumarin-3-carbonyl)- and 3-(7-dimethylaminocoumarin-3-carbonyl)-2-oxazolones (IIa and IIb) were synthesized as fluorescent labeling reagents for high-performance liquid chromatography (HPLC). Treatment of 7-methoxy- and 7-dimethylaminocoumarin-3-carboxylic acids (Ia and Ib) with diphenyl 2-oxo-3-oxazolinylphosphonate in the presence of triethylamine in dichloromethane gave IIa and IIb in 45% and 26% yields, respectively. Compounds IIa and IIb reacted with primary and secondary amines at room temperature in chloroform to give the corresponding fluorescent 7-methoxy- and 7-dimethylamino-3-carboxamides (IIIa-i and IVa-i). A mixture of primary amines was labeled with IIa and chromatographed on a reversed-phase HPLC column (mobile phase : methanol-water) with a fluorescence detector. The detection limit of a test compound, benzylamine, was 19 fmol/100 μl by the use of IIa.

Whereas 2-(polyfluoroalkyl)chromones activated by electron-withdrawing substituents in the benzene ring react with 2-(1-phenylalkylidene)malononitriles in the presence of triethylamine in dichloromethane to produce a wide range of polyfunctionalized benzophenones and dihydroxanthones, their reactions with ethyl α-cyano-β-methylcinnamate under the same conditions took an entirely different course and gave mainly m-terphenyl derivatives. The difference in behavior between the ylidene derivatives of malononitrile and those of ethyl cyanoacetate is remarkable.

Regioselective sulfonylation of 6,1′,6′-tri- O-tritylsucrose through dibutylstannylation: synthesis of 4′- O-sulfonyl derivatives of sucrose

3-Formylchromones react with ylidenemalononitriles in the presence of triethylamine in dichloromethane to produce the target electron-deficient dienes connected to the chromone system with excellent E-selectivity and in good yields. In a similar manner, their reaction with ethyl α-cyano-β-methylcinnamate gave a mixture of E,Z- and E,E-isomeric chromonyl dienes, from which the former could be isolated in a pure state by crystallization.

A sensitive LC method for the determination of alcohols, using fluorescent condensation agent carbazole-9-N-acetylbenzne-disulfonate(CABS), has been developed. A mixture of alcohols and triethylamine catalyst in dichloromethane or chloroform is treated with CABS to give quantitative yields of esters. Emission maximum for the derivatized alcohols is 365 nm (λex 335 nm). The labeled derivatives are very stable, no significant decomposition is observed after heating in 40% at 40°C for 24 h. The method, in conjunction with a multigradient program, offers baseline resolution of common alcohol derivatives on a reversed-phase C18 column. Studies on derivatization conditions indicate that primary and secondary alcohols react very fast with CABS in the presence of triethylamine in dichloromethane or chloroform to give the corresponding fluorescent derivatives. This method is more convenient and more efficient than previous methods which require prior conversion of carboxylic acids to acyl chlorides. The separation of alcohol derivatives has good reproducibility and the rsd's (n=5) for 50 pmol of each alcohol are 4%. Detection limits are at the fmol level.

[92486-00-5] C12H13NO2S2 (MW 267.36) InChI = 1S/C12H13NO2S2/c14-11(13-6-7-17-12(13)16)9-15-8-10-4-2-1-3-5-10/h1-5H,6-9H2 InChIKey = IXLHEGXRGRQHET-UHFFFAOYSA-N (synthon for α-benzyloxy carboxylic esters, amides, or aldehydes;2, 3 enolate precursor for the diastereo- and enantioselective aldol reactions4) Physical Data: mp 81.0–82.0 °C. Form Supplied in: slightly yellow crystals Preparative Method: methyl 2-hydroxyacetate is converted to methyl 2-benzyloxyacetate (1, NaH; 2, BnBr, DMF, 0 °C to rt, 80%). The acetate is then treated with LiOH·H2O (1.25 equiv) in THF–H2O at rt to give 2-benzyloxyacetic acid (99%). The acid is converted to the corresponding acid chloride (oxalyl chloride (2.7 equiv, 60 °C, 1.5 h), which is treated with thiazolidine-2-thione in the presence of triethylamine in dichloromethane to give the title reagent 1 (81% from the acid). Handling, Storage, and Precautions: use in a fume hood.

(2S,4aR,8aS)-Cis,cis-, (2R,4aS,8aR)-cis,cis-, rac-cis,cis-, and rac-trans,cis-decahydro-2-naphthyl-N-n-butylcarbamates are synthesized from condensation of (2S,4aR,8aS)-cis,cis-, (2R,4aS,8aR)-cis,cis-, rac-cis,cis-, and rac-trans,cisdecahydro- 2-naphthols, respectively, with n-butyl isocyanate in the presence of triethylamine in dichloromethane. Optically pure (2S,4aR,8aS)-(-)- and (2R,4aS,8aR)-(+)-cis,cis-decahydro-2-naphthols are resolved by the porcine pancreatic lipase- catalyzed acetylation of decahydro-2-naphthols with vinyl acetate in t-butyl methyl ether. Absolute configurations of (2S,4aR,8aS)-(-)- and (2R,4aS,8aR)-(+)- cis,cis-decahydro-2-naphthols are determined from the ¹⁹F NMR spectra of their Mosher's ester derivatives. (2S,4aR,8aR)-Trans,cis- and (2R,4aS,8aS)-trans,cis-decahydro-2-naphthols can't be resolved from the porcine pancreatic lipase-catalyzed acetylation of decahydro-2-naphthols with vinyl acetate in t-butyl methyl ether. For the inhibitory potency of Pseudomonas lipase, (2S,4aR,8aS)-cis,cis-decahydro-2-naphthyl-N-n-butylcarbamate is 3.5 times more potent than (2R,4aS,8aR)-cis,cis-decahydro-2-naphthyl-N-n-butylcarbamate; racemic cis,cis-decahydro- 2-naphthyl-N-n-butylcarbamate is about the same with trans,cis-decahydro-2-naphthyl-N-n-butylcarbamate. These inhibitors also show similar effects on porcine pancreatic lipase.

A hybrid compound 5: (E)-6-hydroxy-2-oxo-2H-chromen-7-yl 3-(4-hydroxy-3-methoxyphenyl)acrylate composed of (E)-3-(4-hydroxy-3-methoxyphenyl)acrylic acid (ferulic acid) 1 and 6,7-hydroxycoumarin (esculetin) 3 was prepared in a 61% yield by the esterification reaction of protected ferulic acid 2a with esculetin 3 in the presence of triethylamine in dichloromethane for 3 h, followed by deprotection using 3M HCl. The structure of compound 5 was confirmed by 1H, 13C NMR spectroscopy, mass-spectrometry and elemental analysis.

Synthesis of electron-deficient dienes bearing a chromonyl moiety via the reaction of 3-formylchromones with ylidenemalononitriles and ethyl α-cyano-β-methylcinnamate

The oxidation of primary and secondary alcohols with ion-supported methyl sulfoxide and oxalyl chloride in the presence of triethylamine in dichloromethane efficiently proceeded to give the corresponding aldehydes and ketones, respectively, in good yields with high purity. Isolation of the product was achieved very easily by simple diethyl ether extraction of the reaction mixture and subsequent removal of solvent from the extract. The reaction did not produce any unpleasant odor. Furthermore, ion-supported methyl sulfide was recovered in good yield and could be re-oxidized to ion-supported methyl sulfoxide for reuse in the same oxidation.

A series of novel functionalized azetidinones containing the benzotriazole moiety were synthesized stereoselectively by a ­reaction of benzotriazolylacetic acid, aromatic amines, and ­Mukaiyama’s reagent in the presence of triethylamine in dichloromethane at ambient temperature. This transformation generates a four-membered lactam and presumably proceeds via in situ generation of benzotriazolylketene as a heteroarylketene. In contrast to the products obtained from the reaction of pyrrolylketene with imines in which cis -azetidinones were formed as major products, the generated benzotriazolylyketene reacted with imines forming the trans -lactams as major products.