3,4-disubstituted-4,5-dihydro-1H-pyrazoles and a method of preparation

A process for preparing a 3,4-di-substituted-4,5-dihydro-1H-pyrazole compound of the formula ##STR15## wherein Y represents a 5-substituted-2-pyridinyl, 6-substituted-3-pyridinyl, (6 or 7)-substituted-2-quinolinyl, (6 or 7)-substituted-3-quinolinyl, 5-substituted-2-pyrimidinyl, 2-substituted-5-pyrimidinyl, 5-substituted-2-pyrazinyl, or 6-substituted-3-pyridazinyl moiety wherein said substituents are selected from F, Cl, Br, CN, COQ, CF.sub.3, OR', SR', NO.sub.2, and OAr or a 5-membered aromatic heterocyclic ring moiety containing one ring oxygen or sulfur atom and one or two ring nitrogen atoms, which moiety is optionally substituted with one substituent selected from F, Cl, Br, CN, COQ, R, OR', SR', SOR', SO.sub.2 R', NO.sub.2, and OAr and, in those moleties containing only one ring nitrogen atom, optionally additionally substituted with a F substituent;

• X represents phenyl optionally substituted in the 4-position with F, Cl, Br, CN, COQ, R, OR', SR', SOR', SO.sub.2 R', NO.sub.2, or OAr and/or in the 3-position with F, Cl, Br, CN, R, or OR';
• Q represents OR", SR", NH.sub.2, NHR", or NR".sub.2 ;
• R represents C.sub.1 -C.sub.3 alkyl, C.sub.2 -C.sub.3 alkenyl, or C.sub.2 -C.sub.3 alkynyl optionally singly to completely substituted with fluorine or chlorine;
• R' represents C.sub.1 -C.sub.3 alkyl optionally singly to completely substituted with fluorine or chlorine;
• R" represents C.sub.1 -C.sub.4 alkyl, C.sub.3 -C.sub.4 alkenyl, or C.sub.3 -C.sub.4 alkynyl;
• and
• Ar represents phenyl optionally substituted with 1 or 2 compatible substituents selected from F, Cl, Br, CN, COQ, R, OR', SR', SOR', SO.sub.2 R' and NO.sub.2
• which comprises combining an ethanone compound of the formula ##STR16## wherein each of the substituents are defined as above in an optionally chlorinated hydrocarbon solvent with an approximately equimolar amount of an N,N,N',N'-tetra-(C.sub.1 -C.sub.3)alkyldiaminomethane, dipiperidinomethane, dipyrrolidinylmethane or N,N',N"-tri(C.sub.1 -C.sub.3)alkylhexahydro-1,3,5-triazine compound and an approximately equimolar amount of an acid or anhydride of the formula
• R.sup.a --CO.sub.2 H or (R.sup.a --CO).sub.2 O
• wherein R.sup.a represents (C.sub.1 -C.sub.4)alkyl or phenyl, each optionally monosubstituted to completely substituted with F or Cl, or H at about -10.degree. C. to about 30.degree. C. to obtain an intermediate Mannich adduct of the formula ##STR17## wherein each of the substituents are defined as above, and, without isolation, adding hydrazine at about 0.degree. C. to about 50.degree. C., optionally in the presence of an added catalytic amount of a strong acid, to obtain said 3,4-disubstituted-4,5-dihydro-1H-pyrazole compound.