摘要:
A process for the preparation of an .alpha.-ketocarboxylic acid N-tert.-butylamide of the formulaR--CO--CO--NH--C(CH.sub.3).sub.3in whichR is an aliphatic radical with up to 8 carbon atoms, a cycloalkyl radical with 3 to 6 carbon atoms, a phenyl or naphthyl radical or a heterocyclic radical,comprising reacting an acyl cyanide of the formulaR--CO--CNwith tert.-butyl methyl ether of the formula(CH.sub.3).sub.3 C--O--CH.sub.3at a temperature between about 0.degree. and 80.degree. C. in the presence of an acid which is capable of activating the ether of formula (III) under the reaction conditions to give a tert.-butyl carbonium ion, and then hydrolyzing the reaction mixture. Advantageously the acyl cyanide is pivaloyl cyanide or benzoyl cyanide and is reacted with an approximately equimolar amount of the ether in the presence of about 1.1 to 1.5 times the molar amount of concentrated sulphuric acid as the activating acid. The products are useful as intermediates in the synthesis of known herbicides.
摘要:
Dichloromaleic acid diamides of the formula ##STR1## in which R represents an optionally substituted aliphatic radical with up to 8 carbon atoms, a cycloalkyl radical with 3 to 6 carbon atoms or a substituted phenyl radical,which possess fungicidal properties, are produced by reacting a dichloromaleic halide of the formula ##STR2## in which X is halogen,with an amine of the formulaH.sub.2 N--Rin a diluent and in the presence of an acid-binding agent.
摘要:
Aromatic amines which are substituted by C.sub.1 -C.sub.4 -alkoxy in the p-position are prepared by catalytic hydrogenation of the underlying aromatic nitro compounds in a reaction medium comprising sulphuric acid and a C.sub.1 -C.sub.4 -alcohol by a Bamberger type rearrangement at elevated temperature, advantageously by carrying out the catalytic hydrogenation under elevated pressure.
摘要:
Dialkyl carbonates can be prepared by reaction of carbon monoxide with alkyl nitrites in continuous gas phase reaction, in which a platinum metal halide catalyst on aluminum oxides, aluminum oxide hydrates or aluminum hydroxides as support and, if desired, an additive comprising an antimony, bismuth, aluminum, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel compound or a mixture of a plurality thereof on this catalyst are used and hydrogen halide is replaced during the course of the reaction batchwise or continuously in at least the amount which is discharged from the reactor together with the reaction mixture. This results in the formation of dialkyl carbonates in almost quantitative selectivity, while the corresponding dialkyl oxalates can not in most cases be detected. The abovementioned supports are characterized by a BET surface area of more than 1 m.sup.2 /g.
摘要:
Aromatic (di)chlorosulphonic acids and (di)bromosulphonic acids can be prepared by reacting aromatic sulphonic acids with chlorine or bromine respectively, the reaction advantageously being carried out in the melt of the aromatic sulphonic acids.
摘要:
The present process for the preparation of cyclopropylamine by the so-called Hofmann degradation of cyclopropanecarboxamide is characterized in that the cyclopropanecarboxamide is employed in the form of a solution. The new process can be carried out at 5.degree.-35.degree. C. The cyclopropylamine is obtained after introducing the reaction mixture into a concentrated alkali metal hydroxide solution.
摘要:
Aminoaryl-sulphonic acids can be prepared by reaction of arylamines and sulphuric acid at elevated temperature and under pressure, where water formed and, where appropriate, water present as water of dilution, is left in the reaction mixture until the end of the reaction.
摘要:
Substituted benzaldehydes are prepared by reaction of the substituted benzenes from which they are derived with carbon monoxide and hydrogen chloride in the presence of metal halides, the process being performed in the presence of 0.5 to 10 mols of hydrogen chloride per mol of metal halide at a partial pressure of carbon monoxide from 1 to 100 bars and a temperature from -20.degree. C. to +100.degree. C. and, if desired, in the presence of an inert diluent. The substituted benzaldehyde which contains, as a substituent, alkyl with at least 2 carbon atoms, cycloalkyl or optionally substituted benzyl, is prepared by reacting the appropriately substituted benzene with the additional presence of a benzene which does not contain the substituents mentioned, but which is identical in respect of further substituents which are optionally present with the benzene from which it is derived.
摘要:
A process for the preparation of cinnamic acid is provided by the present invention in which an optionally substituted benzaldehyde and alkali metal salt of carboxylic acid and/or alkali metal (bi) carbonate, as condensing agents, are heated up to a temperature of 100.degree.-220.degree. C. and thereafter there is introduced into the so heated mixture acetic anhydride in at least a stoichiometric amount based upon the amount of optionally substituted benzaldehyde employed. The process can be carried out by heating up a reaction mixture to 100.degree.-220.degree. C. which is free of acetic anhydride or one which contains acetic anhydride but less than a stoichiometric amount thereof based upon the amount of optionally substituted benzaldehyde.
摘要:
A method of combatting fungi which comprises applying to fungi or a fungus habitat a fungicidally effective amount of at least one maleic acid N-aralkyl-imide of the formula ##STR1## in which X is hydrogen or halogen,Hal is halogen, andm is 2,3 or 4.Those compounds are new in whichHal is chlorine or bromine, andX is hydrogen or bromine if m is 2, orX is chlorine if m is 4.