Lithium Hydroxide → 1-[(Tert-butoxy)carbonyl]-3-(methoxymethyl)pyrrolidine-3-carboxylic acid

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Reaction Steps

The title compound was prepared according to general procedure B described in connection with Scheme 2. 1-tert-Butyl 3-methyl 3-(methoxymethyl)pyrrolidine-1,3-dicarboxylate (4.5 g, 16.5 mmol) was dissolved in 30 mL of MeOH and a solution LiOH (0.79 g, 33 mmol) in 20 mL was added. The reaction mixture was microwaved at 130° C. for 25 min in 5 vials. The methanol was evaporated and the residue was acidified to pH 1-2 with KHSO4 solid. The acid was extracted with EtOAc (3×50 mL). The combined organic fractions were washed with 1N KHSO4 and with brine and then dried over Na2SO4. The solvent was evaporated to give 7.09 g of the desired acid (91% crude yield). 1H NMR (400 MHz, CDCl3): δ 10.70 (bs, 1H), 3.76 (d, 1H), 3.62-3.41 (m, 5H), 3.35 (s, 3H), 2.34-2.25 (m, 1H), 1.98-1.93 (m, 1H), 1.45 (s, 9H); MS (ESI) m/z: Calculated for C12H21NO5: 259.1. found: 260 (M+1)+.

Provenance & Evidence