Dipyrazoles and their use as bronchodilators
AssigneeMerrell Dow Pharmaceuticals Inc.
InventorsMichael E. Le Tourneau, Norton P. Peet
Life of this patent
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Abstract
A group of variously methyl-substituted[1,2-c:3,4-c']dipyrazoles, cyclohepta[1,2-c:3,4-c']dipyrazoles, and cyclopenta[1,2-c:3,4-c']dipyrazoles useful as bronchodilators are described herein. The compounds are prepared by reacting a 1,3-diketone with hydrazine or methylhydrazine to give tricyclic products optionally followed by catalytic dehydrogenation and/or alkylation with a strong base and methyl iodide to give various other compounds within the scope of the invention.
Claims17
A compound of the formula ##STR8## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently hydrogen or methyl with R.sub.1 and R.sub.3 being positioned on one of the nitrogens in their respective rings with the other nitrogen then being doubly bonded to the adjacent carbon;
- the dotted lines indicate the presence of two conjugated double bonds with the specific position of the double bonds being determined by the position of the R.sub.1 or R.sub.3 substituents;
- Z is --CH.dbd.CH-- or --[C.sub.n H.sub.(2 n-q) (CH.sub.3).sub.q ]-- wherein n is 1, 2 or 3;
- q is 0, 1 or 2;
- and C.sub.n H.sub.(2 n-q) is a straight-chain alkylene.
A method for alleviating bronchial spasm in mammals which comprises administering to a mammal in need thereof a bronchodilating amount of a compound of the formula ##STR14## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently hydrogen or methyl with R.sub.1 and R.sub.3 being positioned on one of the nitrogens in their respective rings with the other nitrogen then being doubly bonded to the adjacent carbon;
- the dotted lines indicate the presence of two conjugated double bonds with the specific position of the double bonds being determined by the position of the R.sub.1 or R.sub.3 substituents;
- Z is --CH.dbd.CH-- or --[C.sub.n H.sub.(2 n-q) (CH.sub.3).sub.q ]-- wherein n is 1, 2 or 3;
- q is 0, 1 or 2;
- and C.sub.n H.sub.(2 n-q) is a straight-chain alkylene.
Dependencies are inferred from the claim text.