[bmimSO3H][OTf]/[bmim][X]andZnNTf/[bmim][X]X=PF6andBF4;efficientcatalyticsystemsforthesynthesisoftetrahydropyrimidin-ones-thionesviatheBiginellireactionHemantkumarM.SavanuraRajeshG.Kalkhambkara⇑GopalakrishnanAridossbcKennethK.Laalib⇑aDepartmentofCh