BTZ043

1344087-80-4

1344087-73-5

1161233-85-7

Synthesis of 2-[(2S)-2-methyl-1,4-dioxa-8-azaspiro[4.5]decan-8-yl]-8-nitro-6-(trifluoromethyl)-4H-benzo[e][1,3]thiazin-4-one (Compound 1) and (2S)-2-methyl-1,4-dioxa-8-azaspiro[4.5]decane as 2-(methylsulfanyl)-6-(trifluoromethyl)-4H-benzo[e][1,3]thiazin-4-one (Compound 1) and (2S)-2-methyl-1,4-dioxa-8-azaspiro[4.5]decane. -Trifluoromethyl-4H-1,3-benzothiazin-4-one was carried out in the following general steps: 3.0 g of Compound 1 was suspended in 15 mL of ethanol followed by the addition of 1.5 g of (2S)-2-methyl-1,4-dioxa-8-azaspiro[4.5]decane. The reaction mixture was stirred at room temperature and then heated to 50-60°C maintained for 20 minutes. Upon completion of the reaction, it was cooled to room temperature and a light yellow solid was precipitated by adding 100 mL of water. The product was isolated by filtration in 76% yield (calculated based on 2-chloro-3-nitro-5-trifluoromethylbenzamide).