4- Chloro-5- 1.3-dimethyl-1 //-pyrazole

When methylene chloride was used as a solvent, it was found that 28 are obtained in minor amounts, while the dominating product is the -coordinated chloro-carbyne species [(> -Tp )Mo(CO)2(=CCl)], whose yield increases abruptly with substitution in the pyrazol-l-yl fragments (3-methyl-, 3,4,5-trimethyl-, and 3,5-dimethyl-4-chloro derivatives) [90AX(C)59,95JCS(D) 1709]. The tungsten analog can be prepared similarly. The chlorocarbyne molybdenum complex follows also from the reaction of the parent anion with triphenylsulfonium cation but conducted in dichloromethane. The bromo- and iodocarbyne derivatives are made similarly. 

Chlorination of 6-(4-chloro-3-methylphenyl) -(3,5-dimethyl-l//-pyrazol-l-yl), 5-dihydropyridazin-3(2//)-one 116 with a mixture of phosphorus pentachloride and phosphorus oxychloride is followed by an elimination of 3,5-dimethyl-177-pyrazole giving the aromatized 3-chloro-6-(4-chloro-3-methylphenyl)pyridazine 117 (Scheme 25) <2005CJC251>. 

Chloro-l,3-dimethyl-4-nitro-l H-pyrazole, 1858 Chlorodimethylphosphine, 0895 /V-Chloro-4,5-dimethyltriazole, 1486... 

Carbamoyl-2-nitroacetonitrile, 1113 5-Chloro-1,3-dimethyl-4-nitro-1 //-pyrazole, 1858 Mercury(II) 5-nitrotetrazolide, 0977... 

Chloro-6,8-dimethyl-l,7-naphthyridine (22) underwent ring fission by hydrazine to give 2,6-dimethyl-4-(pyrazol-3-yl)-3-pyridinamine (23) (H2NNH2 H20, 150°C, sealed, 5 h 65%), confirmed in structure by cycliza-tion with triethyl orthoformate to 7,9-dimethyllpyrazolo 1,5-c pyrido[4,3-e] pyrimidine (24) (reactants, EtOH, reflux, 3 h 60%).1098... 

Pyrazole (3 chloro,4 carboxy,1 methyl 5 sulfonamide) halosulfuron Pyrazole (1.4 dimethyl,2 chloro, 3 formyl) fenpyroximate Pyrazole (2 methyl, 3 amino, 4 carboxy) pyrazosulfuron Pyrazole (2 methyl,4 carboxy, ethyl ester) pyrazosulfuron Pyrazole (1 methyl,2 ethyl,4 chloro 5 carboxy) tebufenpyrad 5 Pyrazolone (1.3 dimethyl) benzofenap, pyrazolinate, pyrazoxyfen Pyridazine (1 phenyl 3 hydroxy, 6 oxo) pyridafenthion... 

A similar preference for cis- or emfo-products is generally observed in the reactions of thermally generated chloro(trichloroethenyl)carbene with a large variety of olefins (see Vol. E 19b, p 740)11. The alkynyl-substituted earbene 4 obtained by photolysis of 5-bromoethynyl-3,3-dimethyl-3//-pyrazole adds exo selectively to 3-cyclohexenone to give an 80 20 mixture of 7-bromo-7-(4-methyl-3-penten-l-ynyl)bicyclo[4.1.0]heptan-3-one (5/6)12. The reaction of chlorophenylcarbene and cyclohexene affords 7-chloro-7-phenylbicyclo[4.1.0]heptane with moderate endo preference (see Vol. E19b, p984), i. 

Metazachlor (21) is a halogenated acetanilide developed by the BASF, with the chemical name 2-chloro-2,6-dimethyl-N-(lH-pyrazol-l-yl-methyl)acetanilide (Stormonth and Woodroffe, 1982). 

The attempted oxidation of pyrazole derivatives with electron-withdrawing substituents (R = Me R R = COOCH3 R = CHO Scheme 91) failed (2001UP4). For the same reason the oxidation of the triple bond in 4-chloro-5-(2-chloro-5-nitrophenylethynyl)-1,3-dimethyl-1/f-pyrazole was also unsuccessful. 

The universal synthetic method used to prepare an Ir(C N)2(LX)-type complex is shown in Fig. 5. Dimer complex [Ir(C N)2Cl]2 is readily prepared from reaction of the ligand precursor and IrCl3-nH20 [79], and chloro-ion ligands can be subsequently replaced with an LX chelate. The most studied ancillary ligand LX is acac, but it can be varied with other monoanionic bidentate ligands, such as picolinic acid, N-methylsalicylimine [23], 2-(5-phenyl-4//-[l,2,4]triazol-3-yl)-pyr-idine [28], 2,2,6,6-tetramethyl-3,5-heptanedionate, 1-phenyl-4,4-dimethyl-1,3-pen-tanedionate, l,3-diphenyl-l,3-propanedionate, pyrazolyl, pyrazolyl-borate [80], and (2-pyridyl) pyrazolate derivatives [81]. 

Chloro-3,5-dimethyl- l//-pyrazol-1 -yl)(furan-2-yl)methanone (3b) Yield 85%... 

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