Hv. Patel et al., NOVEL SYNTHESIS OF SUBSTITUTED CHLORO-3-(2H)-PYRIDAZINONES FROM PENTANE-2,3,4-TRIONE 3-ARYLHYDRAZONES, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 31(4), 1992, pp. 273-275
Pentane-2,3,4-trione 3-arylhydrazones (1) on treatment with equimolar
quantity of NaH, followed by addition of chloroacetyl chloride (2) aff
ord the N-chloroacetyl derivatives (3) along with the cyclised product
s 5. Compounds 3 on treatment with NaH undergo cyclisation of 5 which
are also obtained in good yields by treatment of 1 with 2 in the prese
nce of excess NaH. Alternatively, pyridazinones (5) are obtained by tr
eatment of 1 with 2 in the presence of either conc. H2SO4 or p-TsOH. T
he structures of these compounds have been elucidated on the basis of
IR, PMR, C-13 NMR and mass spectral data and elemental analysis.