Efficient synthesis of 4-phosphinoyl-4,5,6,7-tetrahydro-2H-indazol-3-ylamines

We described in this paper an efficient synthesis of variously substituted 4-phosphinoyl-4,5,6,7-tetrahydro-2H-indazol-3-ylamines involving nucleophilic addition of hydrazine on β-ketothioamides as key-step.