Dimethyl Sulfide → Ethyl 2'-iodo-5',7'-dihydro-4'H-spiro[cyclopropane-1,6'-pyrazolo[1,5-a]pyrazine]-3'-carboxylate

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Reaction Steps

To a solution of Intermediate 350B (1.1 g, 3.05 mmol) in THF (10 mL) was added BH3.DMS (0.578 mL, 6.09 mmol, 2M) and the resulting solution was stirred at 40° C. for 18 h. The reaction mixture was cooled to RT, quenched with ethanol (10 mL) and heated to reflux for 1 h. Reaction mixture was concentrated under reduced pressure. The crude product was purified by silica gel chromatography (24 g REDISEP® column, eluting with 2% MeOH in CHCl3). Fractions containing the product were combined and evaporated to afford Intermediate 350C (0.7 g, 66%) as a gummy solid. MS(ES): m/z=348 [M+H]+.

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