But the yields were moderate (20–50%). Ultimately
multistep synthetic strategies emerged, improving the yield,
but they still lack the simplicity of one-pot synthesis [1c,5].
In view of the versatile properties of dihydropyrimidinones,
the development of practical synthetic strategy is of
immense importance. Efforts in this direction have led to
the development of many synthetic methodologies involving
various Lewis acid and transition metal salt combinations