Ammonium Chloride → rac-ethyl 2-((4S,6S,7R)-4-(4-chloro-2-methylphenyl)-1,3,7-trimethyl-4,6,7,8-tetrahydro-1H-pyrazolo[3,4-e][1,4]thiazepin-6-yl)acetate

Participants

Reaction Steps

A solution of ethyl 2-(4-(4-chloro-2-methylphenyl)-1,3,7-trimethyl-4,6-dihydro-1H-pyrazolo[3,4-e][1,4]thiazepin-6-yl)acetate (0.85 g, 1.97 mmol) in MeOH (3.94 mL) was cooled to about 0° C. To the reaction mixture was added sodium tetrahydroborate (0.298 g, 7.88 mmol) portionwise. The reaction mixture was allowed to slowly warm to ambient temperature and stirred for about 16 h. The reaction mixture was cooled to about 0° C. and then saturated aqueous NH4Cl (10 mL) was added. The mixture was partially concentrated under reduced pressure and EtOAc (20 mL) was added. The layers were separated and the aqueous layer was back extracted with EtOAc (10 mL). The combined organic layers were dried over MgSO4, filtered and concentrated under reduced pressure. The crude material was purified by column chromatography (SiO2, EtOAc/DCM 100:0 to 0:50) to afford rac-ethyl 2-((4R,6S,7R)-4-(4-chloro-2-methylphenyl)-1,3,7-trimethyl-4,6,7,8-tetrahydro-1H-pyrazolo[3,4-e][1,4]thiazepin-6-yl)acetate (0.15 g, 0.37 mmol, 19%) LC-MS (Table 1, Method g) Rt=2.58, m/z 408 (M+H)+and rac-ethyl 2-((4S,6S,7R)-4-(4-chloro-2-methylphenyl)-1,3,7-trimethyl-4,6,7,8-tetrahydro-1H-pyrazolo[3,4-e][1,4]thiazepin-6-yl)acetate (0.39 g, 0.97 mmol, 49%) LC-MS (Table 1, Method g) Rt=2.48, m/z 408 (M+H)+.

Provenance & Evidence