A Convenient Synthesis of DI-(Benzyloxycarbonyl)-Protected Guanidines

N,N′-di-(benzyloxycarbonyl)-S-methylisothiourea can be used in the mercury (II) promoted synthesis of bis-benzyloxycarbonyl protected guanidines.     

A Simple Method for the Synthesis of Unsymmetrical Trisubstttuted Guanidines

A simple method for the synthesis of sweet tasting N, N′, N″-trisubstituted guanidines is described. The key intermediate, carbonimidoyl dichloride 6 was prepared using a known method. Reaction of 6 with cydooctylamine followed by the sodium salt of 5-aminomethyltetrazole or the sodium salt of glycine afforded the desired guanidine. When the carbonimidoyl dichloride was allowed to react with (S)-α-phenethylamine followed by the sodium salt of glycine, the guanidine sweetener 2 was obtained.     

A Convenient Syntheses of some New Substituted Guanidines

The cyanamides of 2,6-dimethylaniline, N-methyl-α, β -naphthylamines, 2-methylpiperidine and indoline yielded their respective guanido derivatives on treatment with dry ammonia and their structures have been characterized through spectral studies.     

A Convenient Method for the Synthesis of Aminomethylmonoalkylphosphinate

Starting from the readily available 4‐methylbenzoic acid, an efficient protocol for the preparation of ethyl 4‐(aminomethyl) benzyl (methyl) phosphinate ( 1 ), a novel aminomethylmonoalkylphosphinate was reported in this communication. The important step involves the selective monochlorination of phosphonic ester by POCl₃ and forming the phosphonochloridate, and followed by nucleophilic addition of CH₃MgBr to the acid chloride intermediate.     

A Convenient Method for Synthesis of Gem-bromochlorocyclopropanes

Gem-bramochlorocyclopropanes can be prepared by a convenient method based on the reaction of the mixtures of haloforms and tetrahalomethanes or hexahaloethane with powdered sodium hydroxide.     

A Convenient Method for the Synthesis of bis-Trifluoroethyl Phosphonoacetates

bis-Trifluoroethyl phosphonoacetates were easily obtained by condensation of bis-trifluoroethyl alkylphosphonates with alkyl chloroformates in the presence of 2 equivalents of lithium hexamethyldisilazane (LiHMDS).     

A Convenient Method for the Synthesis of Distamycin Analogue

A novel distamycin analogue was synthesized by chloroform reaction and DCC/HOBT coupling reaction without using amino protection and deprotection.     

A Convenient Method of N-Methylphthalimide Synthesis

We suggest a convenient method to obtain N-methyiphthalimide with a high yield in the reaction of phthalic anhydride with aqueous methylamine.     

A Versatile Method for the Synthesis of cis-2-Aminomethylcyclanols

Reduction of cis-2-phenyl-4a, 5,6,7,8,8a-hexahydro-4H-1,3-benzoxazine and its homologue derivatives 1-4 resulted in N-benzyl- or N-unsubstituted alicyclic 1,3-amino alcohols 5—12, depending on the conditions used.

     

A Convenient Method for the Asymmetric Synthesis of KAD-1229

A new method for preparation of the potent hypoglycemic KAD-1229 was developed.The key step of this method is diasteroselective alkylation in high optical purity and good yield by using easily available Oppolzer‘s camphor sultam as chiral auxiliary.     

A Simple Convenient Method for the Synthesis of 1-Iodoalkynes

Reaction of terminal alkynes with ethylmagneslum bromide In THF followed by the addition of lodine In THF gives 1-lodoalkynes In excellent yields (90–96%).     

A Convenient Method for the Synthesis of Cyclic Imino Ethers

A facile procedure for the preparation of cyclic imino ethers from thiocaprolactam and chloroformates is described.     

A Convenient Method for Synthesis Methyl Ester of Naproxen

α-Arylpropionic acids are a class of nonsteroidal anti-inflammatory drugs with a substantial size of market. Ibuprofen and naproxen are the important members of this family. Since carbonylation catalyzed by transition metal complexes provides an environmentally benign process for their synthesis, there have been numerous patents and publications related to the carbonylation of alcohols and olefins to produce α-arylpropionic acids or their esters^[1-4]. We have studied the carbonylation of α-(6'-methoxy-2'-naphthyl) ethanol to methyl ester of naproxen using PVP-PdCl₂-CuCl₂/PPh₃ catalyst system. Good conversion and selectivity were obtained under mild conditions.     

A Facile Synthesis of New Thiophosphinyl Guanidines

Sodium thiophosphinyl cyanamide Na[Ph₂P(S)NCN] reacts with aryl-and alkylammonium chlorides [RNH₃]Cl under mild conditions to the corresponding aryl- or alkylammonium thiophosphinyl cyanamides, which rearrange to N-aryl(alkyl)-N′-thiophosphinyl guanidines in a Wöhler's type reaction.     

A Convenient Method for the Synthesis of α-Functionalized Chlorophosphonic Esters

α-Functionalized chlorophosphonic monoesters were easily prepared by a selective chlorination of the corresponding phosphonic diesters with phosphorus oxychloride.     

A Convenient Method of Synthesis of Dialkyltellurides and Dialkylditellurides

Elemental tellurium is reduced by thioureadioxide in alkaline medium, leading to disodium telluride or ditelluride, depending on the amount of thioureadioxide used. The intermediate disodium telluride or ditelluride reacts “in situ” with alkyl halides to give dialkyltellurides or dialkylditellurides in high yield.     

A Convenient Method of Synthesis of Ferrocenylethynyl Ketones

It is well known that molecules possessing extensive conjugated π-electron systems exhibit large non-linear optical properties,[1,2] but the compounds of ferrocenylethynyl ketones have not been reported so far. We now reported preparation of some ferrocenylethyl ketones. These new ethynylketones containing ferrocenyl were prepared conveniently via coupling reaction catalyzed by PdCl2(PPh3)2/PdBzCl(PPh3)2-CuI from ferrocenylethyne and acyl chlorides. This coupling reaction proceeded smoothly in argon and free-water atmosphere at room temperature and gave coupling products in satisfactory yields. All products were characterized by 1H NMR, MS, IR and UV spectra.     

Rapid and Convenient Method for the Synthesis of Symmetrical Disulfides

Abstract

We present here the results on the use of 1,3,5-triazo-2,4,6-triphosphorine-2,2,4,4,6,6-hexachloride as an efficient promoter in the conversion of thiols to the corresponding symmetrical disulfides under solvent-free conditions. Aromatic thiols bearing electron donating and electron withdrawing groups, heteroaromatic, and alkyl thiols reacted efficiently to afford excellent yields of disulfides in short reaction times after easy work-up. Different functional groups including carboxyl, methoxy, methylthio, and halogen are tolerated.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables.     

胍类化合物的合成进展

胍类化合物是精氨酸残体的一部分，它在具有生物活性的蛋白质、肽中起着重要作用，从天然产物分离得到的胍类化合物大部分具有生理活性，如抗病毒、抗肿瘤、抗艾滋病等。所以，在温和条件下高产率的合成胍类化合物显得非常重要。本文综述了胍类化合物的合成进展。参考文献32篇。     

A Convenient Synthesis of N‐Boc‐Protected α‐Aminonitriles from α‐Amidosulfones

Abstract

Synthesis of N‐Boc‐protected α‐aminonitriles starting from N‐Boc‐protected α‐aminosulfones is described. Treatment of the sulfone with two equivalents of potassium cyanide in 2‐propanol or dichloromethane‐H₂O under phase transfer condition affords crystalline N‐Boc‐protected α‐aminonitriles in good yield. Hydrolysis of the aminonitriles provides a convenient access to racemic α‐amino acids.