Abstract: The present invention relates to novel hardeners for curing epoxy resins and to cure accelerants for the accelerated curing of epoxy resins comprising, in each case, at least one compound from the group of esters of phosphorus-containing acids according to Formula (I), wherein there applies to Formula (I): wherein there applies to the radicals R1, R2, R3, R6, X and indices m, n, p, simultaneously or independently of one another: R1, R2=simultaneously or independently of one another, hydrogen or alkyl, R3=alkyl, aryl, —O-alkyl, —O-aryl, —O-alkylaryl or —O-arylalkyl, R6=hydrogen, alkyl or —NHC(O)NR1R2, X=oxygen or sulphur, m=1, 2 or 3, n=0, 1 or 2, wherein there applies: m+n=3 p=0, 1 or 2.

Abstract: The present invention relates to novel hardeners for curing epoxy resins and to cure accelerants for the accelerated curing of epoxy resins comprising, in each case, at least one compound from the group of esters of phosphorus-containing acids according to Formula (I), wherein there applies to Formula (I): wherein there applies to the radicals R1, R2, R3, R6, X and indices m, n, p, simultaneously or independently of one another: R1, R2=simultaneously or independently of one another, hydrogen or alkyl, R3=alkyl, aryl, —O-alkyl, —O-aryl, —O-alkylaryl or —O-arylalkyl, R6=hydrogen, alkyl or —NHC(O)NR1R2, X=oxygen or sulphur, m=1, 2 or 3, n=0, 1 or 2, wherein there applies: m+n=3 p=0, 1 or 2.

Abstract: A process is described for preparing 3-amino-4,4,4-trifluorocrotonic esters of the formula (I) or the E/Z isomers or tautomeric forms thereof where R1 and R2 are each independently hydrogen, an optionally substituted linear C1–C4-alkyl radical or an optionally substituted benzyl radical and R3 is methyl or ethyl, which comprises a) reacting an alkyl trifluoroacetate with an alkyl acetate of the formula CH3—CO—OR3 and an alkali metal alkoxide to give an enolate of a trifluoroacetoacetic ester of the formula (II) where M is sodium or potassium and R3 is as defined above, and subsequently b) allowing the alkali metal enolate of the trifluoroacetoacetic ester from stage a) to react without further purification directly with an amine of the formula NHR1R2 in the presence of an acid to give the 3-amino-4,4,4-trifluorocrotonic ester. With the aid of this two-stage process, the 3-amino-4,4,4-trifluorocrotonic esters can be prepared in high yields without significant by-products.

Abstract: The present invention provides a process for preparing 2-amino-4-chloro-6-alkoxypyrimidines by reacting the 2-amino-4,6-dichloropyrimidine with an alkali metal alkoxide or a mixture of alkali metal hydroxides and an alcohol, in which the reaction is effected in a polar aprotic solvent (or solvent mixture), the solvent is subsequently distilled off to an extent of >30% and the product is precipitated by adding water during or after the distillation. This process, in which the polar aprotic solvent used may in particular be acetone and which can be performed at temperatures between 5 and 60° C., allows 2-amino-4-chloro-6-alkoxypyrimidines and in particular 2-amino-4-chloro-6-methoxypyrimidine to be prepared in high yields and at simultaneously very marked purity in a particularly economically viable and environmentally benign manner.

Abstract: A process is described for preparing 3-amino-4,4,4-trifluorocrotonic esters of the formula (I) or the E/Z isomers or tautomeric forms thereof where R1 and R2 are each independently hydrogen, an optionally substituted linear C1-C4-alkyl radical or an optionally substituted benzyl radical and R3 is methyl or ethyl, which comprises a) reacting an alkyl trifluoroacetate with an alkyl acetate of the formula CH3—CO—OR3 and an alkali metal alkoxide to give an enolate of a trifluoroacetoacetic ester of the formula (II) where M is sodium or potassium and R3 is as defined above, and subsequently b) allowing the alkali metal enolate of the trifluoroacetoacetic ester from stage a) to react without further purification directly with an amine of the formula NHR1R2 in the presence of an acid to give the 3-amino-4,4,4-trifluorocrotonic ester. With the aid of this two-stage process, the 3-amino-4,4,4-trifluorocrotonic esters can be prepared in high yields without significant by-products.