Lithium Hydroxide → HCID 70817773, compound

Participants

Reaction Steps

To a solution of ethyl 2-methyl-2-(methylsulfonyl)-4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]butanoate (28 g, 0.07 mol) in THF (100 mL) was added a solution of LiOH (4.2 g, 0.017 mol) in H2O (50 mL). The mixture was stirred at room temperature for 5 h. The THF was removed under reduced pressure and the aqueous phase was washed with EtOAc (50 mL×2) and then acidified with aqueous HCl (3 M). The solid precipitate was filtered to give the first batch of (2-methyl-2-(methylsulfonyl)-4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]butanoic acid. The mother liquid was refrigerated for 20 h, filtered to give the second batch of 2-methyl-2-(methylsulfonyl)-4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]butanoic acid. The two batches were combined the and dried to give 2-methyl-2-(methylsulfonyl)-4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]butanoic acid (13 g, 50%) as a white solid.

Provenance & Evidence