PMGB

pyrimidinone:

A mixture of carboxamide (0.007 mol) and potassium tert-butoxide (0.011 mol) in 20 mL tert-butanol (caution- highly flammable reagent) was heated in a sealed tube at 90 ^oC for 6 h. The reaction mixture was cooled, tert-butanol was removed in rotavap and the residue was added to ice. Stirring for a while gave a solid (product) which was filtered, washed with water and then ether, and dried to give the corresponding pyrimidinone (white solid, 96% yield).

Reference: Dale, D J.; Dunn, P. J.; Golightly, C.; Hughes, M. L.; Levett, P. C.; Pearce, A. K.; Searle, P. M.; Ward, G.; Wood, A. S. Org. Proc. Res. Dev. 2000, 4, 17-22.

Pyrazole esters:

To a mixture of diethyloxalate (0.07 mol) and the ketone (0.07 mol) cooled in a water bath was added sodium methoxide in portions (0.07 mol) (exothermic). The mixture was heated to 55 ^oC for 1 h. Then it was acidified with 50 mL saturated aqueous citric acid solution and extracted with 50 mL dichloromethane, dried (MgSO₄) and evaporated to give a yellow oil. To the yellow oil (intermediate) in 50 mL ethyl acetate in a water bath was added p-toluenesulfonic acid (0.3 g) followed by hydrazine hydrate (6 mL) in 25 mL ethyl acetate drop wise (exothermic) and stirred at room temperature for 1 h (yellow solid precipitated). The mixture was neutralized with saturated aqueous sodium bicarbonate solution, extracted with ethyl acetate, washed with brine and dried (Na₂SO₄) to give the corresponding mixture of pyrazoles (brown oil, 95%).    

Reference: European Patent 1 077 214 A1