Sodium borohydride → 6,7-dichloro-4-cyclopropyl-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide

Participants

Reaction Conditions

Reaction Steps

Finely ground NaBH4 (1 g) is added to a solution of 6,7-dichloro-4-cyclopropyl-4H-1,2,4-benzothiadiazine 1,1-dioxide from the Step above (1.9 g) in isopropanol (50 mL) and then heated at 50-55° C. for 5-10 minutes. The solvent is removed by evaporation under reduced pressure. The residue is taken up in water (50 mL) and brought to acid pH by adding 6N HCl. The title product is extracted with dichloromethane (3×30 mL). The organic phase is dried over MgSO4 and filtered. The filtrate is evaporated to dryness and the residue obtained is recrystallised from methanol/water 1/1 (60 mL).

Provenance & Evidence