A new transformation of 2H-pyran-2-one ring: First synthesis of pyridazino[4,3-c]azepines and their oxidation with Thallium(III) nitrate or copper(II) acetate

Synlett

Volumn , Issue 2, 2000, Pages 254-256

  Kafka, Stanislav ^b   Trebše, Polonca ^a,c   Polanc, Slovenko ^a   Kočevar, Marijan ^a  

^a UNIVERSITY OF LJUBLJANA   (Slovenia)

^b BRNO UNIVERSITY OF TECHNOLOGY   (Czech Republic)

^c UNIVERSITY OF NOVA GORICA   (Slovenia)

Author keywords

Copper(II) acetate; Esters; Heterocycles; Oxidation; Pyridazino 4,3 c azepines; Thallium(III) nitrate

Indexed keywords

2 PYRONE DERIVATIVE; AZEPINE DERIVATIVE; COPPER ACETATE; NITRATE;

AROMATIZATION; ARTICLE; CHEMICAL ANALYSIS; CHEMICAL REACTION; OXIDATION REDUCTION REACTION; SYNTHESIS;

EID: 0033961649     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2000-6481     Document Type: Article

References (20)

1. th Blue Danube Symposium on Heterocyclic Chemistry, June 7-10, 1998, Eger, Hungary (Abstract PO56) and at the conference Slovenski kemijski dnevi (Slovene Chemistry Days), Maribor, Slovenia, September 17-18, 1998 (Zbornik referatov s posvetovanja, p 232).
2. Ellis, G. P. In Comprehensive Heterocyclic Chemistry; Katritzky, A. R., Rees, C. W., Eds.; Pergamon Press: Oxford, 1984; Vol. 3, p 647.
3. Coates, W. J. In Comprehensive Heterocyclic Chemistry II; Katritzky, A. R., Rees, C. W., Scriven, E. F. V., Eds; Pergamon Press: Oxford, 1996; Vol. 6, p 1.
4. (a) Morgan, J. F. J. Am. Chem. Soc. 1948, 70, 2253.
5. (b) Wiley, R. H.; Ellert, H. G. J. Am. Chem. Soc. 1955, 77, 5187.
6. (a) Nölken, E.; Ziegler, E. Monatsh. Chem. 1960, 91, 1162.
7. (b) Deodhar, K. D.; Deval, S. D. Synthesis 1983, 421.
8. (c) Monge, A.; Palop, J. A.; Goñi, T.; Fernández-Alvarez, E. J. Heterocycl. Chem. 1986, 23, 141.
9. (a) Kočevar, M.; Polanc, S.; Tišler, M.; Verček, B. Heterocycles 1990, 30, 227.
10. (b) Trebše, P.; Polanc, S.; Kočevar, M.; Šolmajer T.; Golič Grdadolnik, S. Tetrahedron 1997, 53, 1383.
11. (c) Vraničar, L.; Polanc S.; Kočevar, M. Tetrahedron 1999, 55, 271.
12. Kočevar, M. Acta Chim. Slov. 1996, 43, 143.
13. 7a method.
14. General procedure for the synthesis of pyridazino[4,3-c]azepine-3-carboxylic acid hydrazides 2a-c: A mixture of compound 1 (1 mmol), 98% hydrazine hydrate (2.2 mmol) and p-toluenesulfonic acid hydrate (0.1 mmol) in absolute ethanol (4-8 mL) was refluxed for 7-9.5 h. After cooling, the yellow crystalline substance was filtered off to give TLC-pure 2b-c. Additional amounts of products can be obtained by evaporation of the filtrate to dryness and addition of a small amount of absolute ethanol and cooling. For isolation of 2a the reaction mixture was evaporated and the remaining residue was crystallised from BuOH/MeCN. Total yields 52-65%. Typical procedure for the synthesis of 5 with TTN: To the stirred solution of 2a (222 mg, 1 mmol) in methanol (12 mL), a solution of TTN (1.555 g, 3.5 mmol) in methanol (7 mL) was added, then it was diluted with an additional amount of methanol (5 mL) and stirred for 1 h. The solid was filtered off and washed with methanol (7 mL), the filtrate was evaporated in vacuo, the residue was diluted with water (30 mL) and extracted several times with chloroform to give 179 mg (72%) of TLC-pure product 5a (without optimisation).
15. +, 31%), 191 (100).
16. (a) Hudlický, M. Oxidations in Organic Chemistry; ACS Monograph 186: Washington, DC, 1990.
17. (b) McKillop, A.; Taylor, E. C. In Organic Syntheses by Oxidation with Metal Compounds; Mijs, W. J, de Jonge, C. R. H. J., Eds.; Plenum: New York, 1986; p 695.
18. (c) Kočevar, M.; Mihorko, P.; Polanc, S. J. Org. Chem. 1995, 60, 1466.
19. Tsuji, J.; Nagashima, T.; Thi Qui, N.; Takayanagi, H. Tetrahedron 1980, 36, 1311.
20. Štefane, B.; Kočevar, M.; Polanc, S. Tetrahedron Lett. 1999, 40, 4429.