Improved Large-Scale Preparation of 4-Iodopicolinic Acid

Dimethylformamide showed a dramatic catalytic effect in the chlorination of picolinic acid with thionyl chloride. Methyl 4-chloropicolinate was directly transformed to 4-iodopicolinic acid in a good yield.     

A Convenient Method for the Preparation of Pyran-4-One

In the presence of catalytic quantities of copper and of certain heterocyclic bases, chelidonic acid is decarboxylated in refluxing 1,2,3,4-tetrahydronaphthalene to pyran-4-one in high yield.     

A Convenient,High-Yield Preparation of Butadiene-2,3-Dicarboxylic Acid (Fulgenic Acid)

Butadiene-2, 3-dicarboxylic acid (fulgenic acid) has been reported previously to be avaialable in ca. 1% yield following basic hydrolysis of the corresponding dimethyl ester.¹     

A Convenient Preparation of 2-Ethyl-4-Carboxycyclohexanone

Several years ago in the course of work directed toward the total synthesis of the iboga alkaloids¹, we required relatively large quantities of 2-ethyl-4-carboxycyclonhexanone (1) and its methyl ester as precursors to 3-ethyl-5-carbomethoxycyclohexene. Although it was possible to prepare keto acid 2 from 1,3,5-tricarbomethoxypentane (3) following the published synthesis of 2-methyl-4-carboxycyclohexanone², the overall yield was only 52%. ³ In addition, the isolation and purification of intermediates 4 renders the synthesis rather tedious.     

A Convenient and Effective Preparation of Amino Acids from their Hydrohalide Salts

Although a good method for the conversion of amino acids to their hydrohalide salts has been available for some time,² no broadly useful procedure has been reported for the reverse transformation. Most of the reported techniques are rather involved and show considerable variation in yield for the different amino acids. For instance, a variety of literature examined³ revealed 8 different methods with overall transformations averaging only 66%.     

A Convenient Method for the Large Scale Preparation of (E)-4-Oxo-2-Butenoic Acid Ethyl Ester

A one step synthesis of (E)-4-oxo-2-butenoic acid ethyl ester via the reaction of ethyl 2-ethoxy-2-hydroxyacetate and (formylmethylene)triphenylphosphorane is described. The method proceeds in good yield on a molar scale.     

氨基膦酸树脂对镱的吸附及机理

氨基膦酸树脂 ( APAR)对镱 ( )的吸附在 p H=5 .1时最佳。静态饱和吸附容量为 2 75 mg/g千树脂 ;用 3.0～ 4.0 mol· L- 1HCl能还原洗脱。测得吸附速率常数k2 98=9.5 7× 1 0 - 6 s- 1,等温吸附服从 Freundlich经验式 ,吸附热力学函数△ H0 =1 7.6k J· mol- 1。吸附机理表明 ,APAR功能基上的 N、O与 Yb3+发生配位键合 ,配位摩尔比为 2∶ 1     

A Convenient Method for the Preparation of N-Methoxyamides

A variety of N-methoxyamides is easily prepared from carboxylic acids and N,O-dimethylhydroxylamine hydrochloride in the presence of triphenylphosphine and carbon tetrabromide.     

A Convenient Method for the Preparation of Ellipticine

A convenient method for the synthesis of ellipticine is reported. This synthesis is achieved by modifying the processes of Woodward and Sainsburg. The overall yield of this five step synthesis is 12 percent.     

A Convenient Procedure for the Preparation of Adamantanone

Sinoe adamantanone is a useful and versatile startin material for secondary substituted and ring-transformed adamantanes¹we wish to report on a convenient synthesis of this ketone from adamantans with 98 percent sulfuric acid. Adamantanone may be prepared in basionally the same way, starting from 1-adamantanol, which gives abtter yield and needs a shorter reaction tine²but adamantane affords a more direot routs. The producer reported here is based on a 100-g scale, but this scale may be extended to 1 kg.     

A Convenient Preparation of 2-Carboxy-and 2-Alkoxycarbonyl-r-butyrolactones from Cyclopropane-1, 1-Dicarboxylic Acid

A convenient method for the preparation of 2-carboxy and 2-alkoxycarbony 1-r-butyrolactones from cyclopropane-1, 1-dicarboxylic acid and their mode of formation is described. A possible conformation for the ring is suggested based on the proton coupling data.     

A Convenient Preparation of 1-Mercapto-3-azidocyclo-butane from 1,1-Cyclobutanedicarboxylic Acid

A convenient method for the preparation of cis- and trans-1-mercapto-3-azidocyclobutane from 1,1-cyclobutanedicarboxylic acid is described. The long range “W” coupling pathway was used to distinguish the cis isomer from the trans isomer.     

A Convenient Route for the Preparation of Aromatic Aldehydes

Though a variety of methods^2–5 are available for the synthesis of aldehydes, this area continues to attract attention^6,7 since aldehydes are important intermediates in synthetic organic chemistry. In this communication we present a new route for the synthesis of aromatic aldehydes.     

A Convenient Method for the Preparation of Dialkyl Telluride

Treatment of various alkyl nalides with sodium telluride which is generated by reduction or elemental tellurium with hydrazine hydrate in basic medium using DMF as aprotic solvent affords the corresponding symmetric dialkyl tellurides in moderate to good yields.     

A Convenient Method for the Preparation of Racemic Nicotine

Early studies, in which the first resolution of racemic nicotine was accomplished showed² that 1-nicotine, the principal alkaloid of tobacco, was acutely less toxic than d-nicotine in limited mammalian tests. Later studies^3,4 have generally confirmed this, and some investigators suggest that the physiological effects of d-nicotine may, to some extent, oppose the effects of 1-nicotine, although this matter has been debated. It has been reported⁵ that racemization of 1-nicotine during the course of tobacco smoking leads to the transfer of significant quantities of d-nicotine into the mainstream of cigarette smoke. Where d,1-nicotine has been employed in insecticidal studies, data indicate⁶ that d-nicotine-has alethality equal to that of the-1-isomer. These species differences in response to nicotine antipodes and recent evidence of a central stereospecific nicotine receptor^7,8 have stimulated inter estin efficient routes to the attainment of large quantities of-d-nicotine.     

Dabco/SOCl 2 , Mild,and Convenient Reagent for the Preparation of Symmetrical Carboxylic Acid Anhydrides

Various types of carboxylic acids undergo rapid dehydration with 1,4-diazabicyclo[2.2.2]octane, dabco/thionyl chloride, under mild reaction conditions to afford symmetrical acid anhydrides in high isolated yields.     

Method for a Convenient and Efficient Synthesis of Amino Acid Acrylic Monomers with Zwitterionic Structure

Ampholyte monomers with zwitterionic moiety derived from α‐amino acid, that is, L‐lysine and L‐serine, were obtained using a method in which their copper complexes could be produced in simple steps. The N‐acryloylation of L‐lysine and L‐serine was carried out by reaction between their copper complexes and acryloyl chloride. Specifically, the removal of copper from the copper complex of acryloyl amino acid through the use of 8‐hydroxyquinoline as an organic chelate precipitant increased the yield of the ampholyte monomers with zwitterionic moiety. These syntheses were easily carried out in a three‐step procedure.     

A Convenient Procedure for the Synthesis of Ursodeoxycholic Acid Sulfated Derivatives

The mono- and bis(sulfooxy) derivatives of ursodeoxy-cholic acid are, contrary to a previous report, easily prepared by a very simple direct sulfation procedure.     

A Convenient Method for the Preparation of 4(e)-Hydroxy-and 4(e)-Methoxyadamantan-2-ones

Hydrolysis or methanolysis of 4(a)-(trifluoromethyl-sulfonyloxy)adamantan-2-one affords 4(e)-hydroxy-or 4(e)-methoxyadamantan-2-one, respectively, as major product, both of which are easily separated from minor by-products.