Efficient syntheses of 2-(2,6-dichloro-4-trifluoromethyl-phenyl)tetrahydrocyclopenta, tetrahydrothiopyrano, hexahydrocycloheptapyrazoles and tetrahydroindazoles

Tetrahedron Letters

Volumn 43, Issue 48, 2002, Pages 8639-8642

  Meegalla, Sanath K ^a   Doller, Dario ^a,b   Liu, Ruiping ^a,c   Sha, Deyou ^a,d   Soll, Richard M ^a   Dhanoa, Dale S ^a  

^a JOHNSON AND JOHNSON   (United States)

^b NEUROGEN CORPORATION   (United States)

^c Memory Pharmaceuticals Corporation   (United States)

^d PURDUE PHARMA L P   (United States)

Author keywords

Alkylation; Arylpyrazoles; Boron trifluoride; Synthesis; Trimethylorthoformate

Indexed keywords

2 (2,6 DICHLORO 4 TRIFLUOROMETHYLPHENYL)HEXAHYDROCYCLOHEPTAPYRAZOLE; 2 (2,6 DICHLORO 4 TRIFLUOROMETHYLPHENYL)TETRAHYDROCYCLOPENTAPYRAZOLE; 2 (2,6 DICHLORO 4 TRIFLUOROMETHYLPHENYL)TETRAHYDROINDAZOLE; 2 (2,6 DICHLORO 4 TRIFLUOROMETHYLPHENYL)TETRAHYDROTHIOPYRANOPYRAZOLE; FORMIC ACID DERIVATIVE; INDAZOLE DERIVATIVE; KETONE DERIVATIVE; PYRAZOLE DERIVATIVE; UNCLASSIFIED DRUG;

ALKYLATION; ARTICLE; CHEMICAL REACTION; STEREOSPECIFICITY; SYNTHESIS;

EID: 0037175463     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(02)02158-5     Document Type: Article

References (9)

1. For an excellent review, see: Elguero J. Katritzky A.R., Rees C.W., Potts K.T., Comprehensive Heterocyclic Chemistry. 5:1984;167 Pergamon, Oxford.
2. Lyga J.W., Patera R.M., Plummer M.J., Halling B.P., Yuhas D.B. Pestic. Sci. 42:1994;29-36.
3. Wolf, A. D. US Patent 4 059 434, 1977.
4. Wolf, A. D. US Patent 4 124 274, 1978.
5. To the best of our knowledge, the only precedent for the direct preparation of this type of 5-unsubstituted pyrazoles is: Noravyan, A. S.; Mambreyan, Sh. P.; Vartanyan, S. A. Chem. Abstr. 1978, 89, 6309. For structure determination, see: Bardon, L.; Elguero, J.; Jacquier, R. Bull. Soc. Chim. Fr. 1967, 1, 289-294. For an example of reverse selectivity due to steric hindrance, see: Xenos, C. D.; Catsoulacos, P. Synthesis 1985, 3, 307-309.
6. Aubert T., Tabyaoui B., Farnier M., Guilard R. Synthesis. 9:1988;742-743.
7. Mock W.L., Tsou H. J. Org. Chem. 46:1981;2557-2561.
8. Sakurai H., Sasaki K., Hosomi A. Bull. Soc. Chem. Jpn. 1983;3195-3196.
9. ++1) 354.3.