The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 06, 1981
Filed:
Apr. 03, 1980
Applicant:
Inventors:
Yan R Uldrikis, Elgava, SU;
Ieva E Preisa, Riga, SU;
Gunar Y Dubur, Riga, SU;
Aina A Zidermane, Riga, SU;
Egils A Biseniex, Riga, SU;
Gunar D Tirzit, Riga, SU;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ;
U.S. Cl.
CPC ...
546321 ; 424263 ;
Abstract
2,6-Dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid esters of the general formula: ##STR1## wherein R is a substituted alkyl or terpenyl. A method for preparing said esters comprises reacting esters of acetoacetic acid of the general formula: CH.sub.3 COCH.sub.2 COOR, wherein R is a substituted alkyl or terpenyl, with hexamethylenetetramine in the presence of ammonium acetate in ethanol at its boiling temperature; said esters of acetoacetic acid of the above general formula, hexamethylenetetramine and ammonium acetate can be used in stoichiometric proportions.