Pivalic acid → (S)-1-(3-(((4-amino-2,2-dioxido-1H-benzo[c][1,2,6]thiadiazin-5-yl)oxy)methyl)piperidin-1-yl)-2,2-dimethylpropan-1-one

Participants

Reaction Conditions

Reaction Steps

Pivalic acid (71 mg, 0.692 mmol), 1H-benzo[d][1,2,3]triazol-1-ol (117 mg, 0.865 mmol), and 1-(3-Dimethylaminopropyl)-3-ethyl carbodiimide HCl (166 mg, 10.8 mmol) were placed into a 20 mL microwave flask and diluted with anhydrous CAN (12 mL) then a solution of (S)-4-amino-5-(piperidin-3-ylmethoxy)-1H-benzo[c][1,2,6]thiadiazine 2,2-dioxide hydrochloride (Example 2a, 200 mg, 0.577 mmol) and TEA (320 uL, 2.30 mmol) in DMF (2 mL) was added. The mixture was heated with stirring in the microwave at 130° C. for 1 hour then cooled to room temperature, transferred to 250 mL round bottom flask and concentrated via rotary evaporation. The residue was purified via preparative RP HPLC (10 to 90% ACN in water). The pure fractions were collected and dried then diluted with water (6 mL) and NaHCO3 (100 mg) was added and the solution heated to 90° C. for 15 minutes until the entire compound dissolved. The solution was then cooled to 0° C. and neutralized with 1N HCl solution. The precipitate was collected and dried to provide the title compound (110 mg, 48%). 1H NMR (DMSO-d6, 400 MHz, 80° C.): 1.15 (s, 9H), 1.35 (m, 2H), 1.68 (br s, 1H), 1.85 (br s, 1H), 2.05 (br s, 1H), 2.83 (br s, 2H), 2.16 (br s, 2H), 4.06 (d, J=8 Hz, 2H), 4.12 (d, J=12 Hz, 1H), 4.20 (d, J=16 Hz, 1H), 6.60 (d, J=8 Hz, 1H), 6.76 (d, J=8 Hz, 1H), 7.44 (t, J=8 Hz, 1H), 7.78 (s, 1H), 8.37 (s, 1H), 10.93 (s, 1H). M+H=395.

Provenance & Evidence