Sodium Chloride → (4S)-6-Chloro-4-hydroxy-2-(2-methoxyethyl)-3,4-dihydro-1lambda~6~-thieno[3,2-e][1,2]thiazine-1,1(2H)-dione

Participants

Reaction Steps

A mixture of (S)-3,4-dihydro-6-chloro-4-hydroxy-2H-thieno[3,2-e]-1,2-thiazine-1,1-dioxide (5, 1.2 g) and potassium carbonate (2.1 g) in dimethylsulfoxide (7 mL) was treated with 1-bromo-2-methoxyethane (0.5 eq, 0.25 mL) and the mixture was stirred at ambient temperature for 3 hours. Another 0.25 mL of 1-bromo-2-methoxyethane was then added and the mixture was stirred at ambient temperature for 18 hours. TLC analysis after this period indicated incomplete reaction, so another 0.25 mL of 1-bromo-2-methoxyethane was added and the mixture was stirred at ambient temperature for another 3 hours. At this point, TLC indicated complete reaction. The mixture was poured into saturated aqueous sodium chloride (50 mL) and extracted with t-butyl methyl ether. The organic phase was washed sequentially with 10% aqueous sodium hydroxide, 1:1 5.25% sodium hypochlorite water, and saturated aqueous sodium chloride, dried over sodium sulfate, and stripped of solvent by rotary evaporation. Residual solvent was removed under vacuum to provide 1.1 grams (75%) of (S)-3,4-dihydro-6-chloro-4-hydroxy-2-(2-methoxyethyl)-2H-thieno[3,2-e]-1,2-thiazine-1,1-dioxide as a light yellow oil: IR (film) 3500-3400, 1430, 1340, 1170, 1120, 1080, 1040, 700 cm-1 ; 1H NMR (CDCl3) δ6.98 (s, 1H), 4.57 (br, 1H), 4.33 (dd, 1H, J=4 and 16 Hz), 4.16 (br, 1H), 3.91-3.38 (m, 5 H), 3.31 (s 3H); [α]25D +4.0° (c=1, CH3OH); Analysis for C9H12ClNO4S2 : Calcd: C, 36.30; H, 4.06; N, 4.70. Found: C, 36.23; H, 4.05; N, 4.66.

Provenance & Evidence