Synthesis 2004(18): 2975-2979  
DOI: 10.1055/s-2004-834892
PAPER
© Georg Thieme Verlag Stuttgart · New York

One-Pot Synthesis of 3,4-Dihydro-2H-pyrido[1,2-a][1,3,5]triazin-2-one Derivatives from N-(2′-Pyridinyl)benzoylacetamide and Nitrosobenzenes

Barbara Zaleska*a, Bartosz Trzewika, Ewa Stodolaka, Jacek Grochowskib, Pawe Serdab
a Department of Organic Chemistry, Jagiellonian University, ul. Romana Ingardena 3, 30-060 Kraków, Poland
Fax: 48(12)6340515; e-Mail: zaleska@chemia.uj.edu.pl;
b Regional Laboratory of Physicochemical Analyses and Structural Research, ul. Romana Ingardena 3, 30-060 Kraków, Poland
Further Information

Publication History

Received 28 July 2004
Publication Date:
22 October 2004 (online)

Abstract

A convenient method leading to fused pyrido[1,2-a] [1,3,5]triazine-2-ones is described. It consists in a one-pot, two-step reaction of N-(2′-pyridinyl)benzoylacetamide with nitrosobenzenes. On the other hand, N-(2′-pyridinyl)acetoacetamide provides a C-2 condensation/addition product with nitrosobenzene. N-(2′-Pyridinyl)benzoylthioacetamide and N-(2′-pyridinyl)acetothioacetamide with nitrosobenzene undergo oxidative heterocyclisation leading to [1,2,4]thiadiazolo[2,3-a]pyridine derivatives.

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Compound 4a (C19H14N4O) crystallises in the monoclinic system, space group P21/c, with unit cell parameters a = 1558.71 (5), b = 1331.37 (3), c = 727.70 (2) Å, β = 83.728 (1)°, V = 1.50108 (7) × 109 pm3, Z = 4. The X-ray diffraction data were collected on a KappaCCD (Bruker-Nonius) single-crystal diffractometer using MoKα radiation (55 kV, 30 mA). A total of 11584 reflections were collected and merged to give 3004 independent reflections [R(int) = 0.051] on a single-crystal sample (size 0.3 × 0.2 × 0.15 mm). The structure was solved in space group P21/c by direct methods using the SHELXS86 program and refined by full-matrix least-squares method with SHELXL 97. The differential Fourier map of electron density was featureless with no chemically significant peaks. All hydrogen atoms were located on a difference Fourier map of electron density. Final R indices for I>2σ(I) were equal to R1 = 0.055, wR2 = 0.109, and R1 = 0.0856, wR2 = 0.1240 for all data. The final difference Fourier map of electron density was featureless with the largest peak and hole at 1.7 × 10-7 and -1.5 × 10-7 e·pm-3, respectively. The structural data have been deposited at the Cambridge Crystallographic Data Centre under the reference number CCDC 250196.