Process for making imidazolines and tetrahydropyrimidines from oxazolines and alkylenediamines

• US 4,014,880 A
• Filed: 02/09/1976
• Issued: 03/29/1977
• Est. Priority Date: 02/09/1976
• Status: Expired due to Term

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Dowd, William, Owen, Peter W.
• Primary Examiner(s): Gotts, Lewis
• Assistant Examiner(s): Phillips, D. R.
• Application Number:
  US05/656,558
• Time in Patent Office: 414 Days
• Field of Search: 260/251 R, 260/309.7
• US Class Current: 544/242
• CPC Class Codes: C07D 233/06 with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to ring carbon atoms
• CPC Class Codes: C07D 239/06 having one double bond between ring members or between a ring member and a non-ring member

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.

Claims

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).

2. The process defined by claim 1 wherein the oxazoline reactant is of the formula ##STR4## wherein R is alkyl, aryl, or inertly-substituted alkyl or aryl and R₁ -R₄ are each independently hydrogen, lower alkyl or hydroxy-substituted lower alkyl.

3. The process defined by claim 2 wherein R is alkyl of from 1 to about 20 carbon atoms and R₁ -R₄ are each hydrogen.

4. The process defined by claim 1 wherein reactant (b) is of the formula

5. The process defined by claim 4 wherein R₅ is hydrogen and R₆ is hydrogen, methyl or ethyl.

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

8. The process defined by claim 7 wherein (a) is 2-ethyl-2-oxazoline and (b) is 1,2-ethylenediamine or 1,3-propylenediamine.

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.