Lithium hydroxide, monohydrate → 7-(tert-Butoxycarbonyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine-2-carboxylic acid

HRID 1808386Notes

Reaction equation

O[Li].O.C([C:6]1([C:22]([O-:24])=[O:23])[CH2:21][N:9]2[CH2:10][CH2:11][N:12]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:13][C:8]2=[N:7]1)C>CO.O>[C:17]([O:16][C:14]([N:12]1[CH2:11][CH2:10][N:9]2[CH:21]=[C:6]([C:22]([OH:24])=[O:23])[N:7]=[C:8]2[CH2:13]1)=[O:15])([CH3:20])([CH3:18])[CH3:19]

Participants

Conditions

Temperature: 25 °C

Procedure

LiOH.H2O (8.8 mmol, 4.0 equiv.) was added at 0° C. to a solution of 7-tert-butyl 2-ethyl-5,6-dihydroimidazo[1,2-a]pyrazine-2,7(8H)-dicarboxylate (2.2 mmol, 1.0 equiv.) in methanol/water (2.5:1, 35 ml), and the mixture was then stirred for 2 h at 25° C. When the reaction was complete (TLC monitoring), the methanol was removed in vacuo, the residue was diluted with water (40 ml), and extraction with ethyl acetate (2×40 ml) was carried out. The aqueous phase was then adjusted to pH 2-3 with 1N HCl solution, and the resulting solid was filtered out. The solid was taken up in toluene, and the solvent was then removed in vacuo (2×) to yield the desired product in the form of a white solid. Yield: 68%.

Workup

customthe methanol was removed in vacuo
additionthe residue was diluted with water (40 ml), and extraction with ethyl acetate (2×40 ml)
filtrationthe resulting solid was filtered out
customthe solvent was then removed in vacuo (2×)

Sources & evidence

ORD record: ord-d093a670a0de4843a928e9bcbdc50971
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08357717B2

Reaction notes

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