Preparation of DL-β-Leucine. Amino Acids. XV

By application of the Arndt-Eistert reaction to the diazoketone of N-phthaloyl-DL-valine, racemic B-leucine h as been prepared and tested against Staphyiococcus aureus, B. pyocyaneus, E. coli and Enterococcus

Preparation of DL-β-Leucine. Amino Acids. XV

By application of the Arndt-Eistert reaction to the diazoketone of N-phthaloyl-DL-valine, racemic B-leucine h as been prepared and tested against Staphyiococcus aureus, B. pyocyaneus, E. coli and Enterococcus

Note on the Preparation of 5-Phenyl-oxazolidine-2,4-dione

5- Phenyl-oxazolidine- 2,4 - dione has been prepared by the condensation of ethyl mandelate witth guanidine nitrate and subsequent hydrolysis of the 2- imino intermedlate by condensing »acetone-mandelic acid« or ethyl mandelate with urethane; by the condensation of ethyl mandelate with urea or 1- acetyl-3-methyl-urea; by the reaction of ethyl a-chloro-phenylacetate with urea or 1-acetyl- 3-methyl-urea and subsequent hydrolysis; by condensing mandelamide with diethyl carbonate. 5-Phenyl-oxazolidine-2,4-dione was furthermore obtained by the alkaline hydrolysis of 1,5 -diphenyl- and 1-methyl-5-phenyl- dialuric acid and 5-bromo-1,5-diphenyl and 5- bromo -1-methyl- 5-phenyl-barbituric acid with subsequent acid hydrolysis of the 2-imino-intermediates and, by the action of alkali on 1-(phenyl-chloroacetyl)-3-phenyl-urea and (phenyl-chloroacetyl)-urea

Note on the Preparation of 5-Phenyl-oxazolidine-2,4-dione

5- Phenyl-oxazolidine- 2,4 - dione has been prepared by the condensation of ethyl mandelate witth guanidine nitrate and subsequent hydrolysis of the 2- imino intermedlate by condensing »acetone-mandelic acid« or ethyl mandelate with urethane; by the condensation of ethyl mandelate with urea or 1- acetyl-3-methyl-urea; by the reaction of ethyl a-chloro-phenylacetate with urea or 1-acetyl- 3-methyl-urea and subsequent hydrolysis; by condensing mandelamide with diethyl carbonate. 5-Phenyl-oxazolidine-2,4-dione was furthermore obtained by the alkaline hydrolysis of 1,5 -diphenyl- and 1-methyl-5-phenyl- dialuric acid and 5-bromo-1,5-diphenyl and 5- bromo -1-methyl- 5-phenyl-barbituric acid with subsequent acid hydrolysis of the 2-imino-intermediates and, by the action of alkali on 1-(phenyl-chloroacetyl)-3-phenyl-urea and (phenyl-chloroacetyl)-urea

Note on the Preparation of Ethyl Cyclohexylidene-Cyanoacetate

Ethyl cyclohexylidene-cyanoacetate has been prepared by the condensation of ethyl cyanoacetate and cyclohexanone under pressure and in the presence of various catalysts i. e. sodium ethoxide, piperidirne pyridine , piperazine , acid amides, soluble salts of amines or quarternary ammonium bases with an organic acid, acetamide, and ammonium acetate and acetic acid

Note on the Preparation of Diethyl Malonate

Chlorsulfonic acid was successfully used as a catalyst in some esterifications. It was found that in the presence of chloirosulfonic acid an ethanolic solution of cyanoacetic acid is simultaneously hydrolyzed and esterified to give diethyl rnalonate with 82-84 % yield, based on chloroacetic acid

Note on the Preparation of Ethyl Phenylmalonate

The procedure based on the method of Wislicenus as reported by Levene and Meyer was simplified in modifying the process described for the preparation of the methyl ester

Note on the Preparation of Ethyl Phenylmalonate

The procedure based on the method of Wislicenus as reported by Levene and Meyer was simplified in modifying the process described for the preparation of the methyl ester

Note on the Preparation of Diethyl Malonate

Chlorsulfonic acid was successfully used as a catalyst in some esterifications. It was found that in the presence of chloirosulfonic acid an ethanolic solution of cyanoacetic acid is simultaneously hydrolyzed and esterified to give diethyl rnalonate with 82-84 % yield, based on chloroacetic acid

Note on the Preparation of Some Thiobarbiturates

It has been shown that barbituric acid derivatives can be prepared in good yield by gradually adding sodium methoxide as condensation catalyst to a cyanoacetic or malonic ester reacting with urea or its derivatives. The principle of the gradual addition of sodium methoxide as condensing agent has now been extended to condensations of some substituted cyanoacetic and malonic esters with thiourea