Process for making imidazolines and tetrahydropyrimidines from oxazolines and alkylenediamines
First Claim
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1. In the method of preparing a 2-imidazoline or a 1,4,5,6-tetrahydropyrimidine by reacting (a) a 2-oxazoline with (b) 1,2-alkylenediamine or a 1,3-alkylenediamine in liquid-phase, the improvement comprising conducting the reaction in the presence of a small but sufficient amount of a Lewis acid to catalyze the reaction between (a) and (b).
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Abstract
The reaction of 2-oxazolines with 1,2- or 1,3-alkylenediamines to form 2-imidazolines or 1,4,5,6-tetrahydropyrimidines is catalyzed by Lewis acids.
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Citations
9 Claims
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1. In the method of preparing a 2-imidazoline or a 1,4,5,6-tetrahydropyrimidine by reacting (a) a 2-oxazoline with (b) 1,2-alkylenediamine or a 1,3-alkylenediamine in liquid-phase, the improvement comprising conducting the reaction in the presence of a small but sufficient amount of a Lewis acid to catalyze the reaction between (a) and (b).
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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5. The process defined by claim 4 wherein R5 is hydrogen and R6 is hydrogen, methyl or ethyl.
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6. The process defined by claim 4 wherein n is 1.
- 7. The process defined by claim 1 wherein the catalyst is of the formula
- space="preserve" listing-type="equation">CrCl.sub.2.sup.. 6H.sub.2 O;
MoO.sub.2 ;
H.sub.2 WO.sub.3 ;
Zn(OAc).sub.2.sup.. 2H.sub.2 O;
CdCl.sub.2.sup.. 2.5H.sub.2 O;
HgCl.sub.2 ;
or AlCl.sub.3.
- space="preserve" listing-type="equation">CrCl.sub.2.sup.. 6H.sub.2 O;
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8. The process defined by claim 7 wherein (a) is 2-ethyl-2-oxazoline and (b) is 1,2-ethylenediamine or 1,3-propylenediamine.
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9. The process defined by claim 1 wherein (a) is 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2,5-dimethyl-2-oxazoline, or 2-undecyl-2oxazoline (b) is 1,2-ethylenediamine, 1,3-propylenediamine or N-hydroxyethyl ethylenediamine and the Lewis acid catalyst is zinc acetate dihydrate.
Specification