3,4-Dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide synthesis

Yield:359-84-2 98%

Reaction Conditions:

with sodium tetrahydroborate in isopropyl alcohol at 20; for 0.0833333 h;

Steps:

1.3 Step 3. Preparation of 3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide

Add 0.91g (5mmol) 4H-benzo[e][1,2,4]thiadiazine 1,1-dioxide and 30mL anhydrous isopropanol to a 100mL double-necked round bottom flask at room temperature, and stir at room temperature Add 0.76g (20mmol) sodium borohydride in batches and monitor the reaction by TLC. After 5 minutes, the reaction is complete. The isopropanol is removed under reduced pressure. A small amount of distilled water is added to the reaction system and the pH is adjusted to 2 with 1mol/L dilute hydrochloric acid. , A large amount of solids were separated out, filtered under reduced pressure, washed with a small amount of distilled water, the obtained solids were dried to obtain 3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-di Oxide 0.9g, yield 98%.

References:

CN111410638,2020,A Location in patent:Paragraph 0023; 0028-0029