Hydrochloric Acid → 3-(1-Carboxycyclopentyl)-2(dibenzylaminomethyl)propanoic acid t-butyl ester
Reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[CH:13]1([C:18]([OH:20])=[O:19])[CH2:17][CH2:16][CH2:15][CH2:14]1.[C:21]([O:25][C:26](=[O:45])[C:27]([CH2:29][N:30]([CH2:38][C:39]1[CH:44]=[CH:43][CH:42]=[CH:41][CH:40]=1)[CH2:31][C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)=[CH2:28])([CH3:24])([CH3:23])[CH3:22].Cl>O1CCCC1>[C:21]([O:25][C:26](=[O:45])[CH:27]([CH2:29][N:30]([CH2:38][C:39]1[CH:40]=[CH:41][CH:42]=[CH:43][CH:44]=1)[CH2:31][C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)[CH2:28][C:13]1([C:18]([OH:20])=[O:19])[CH2:17][CH2:16][CH2:15][CH2:14]1)([CH3:22])([CH3:23])[CH3:24]Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -20 °C
Procedure
To a stirred solution of diisopropylamine (14.98 g, 20.75 ml, 148 mmole) in dry tetrahydrofuran (250 ml) cooled to -30° C. under nitrogen, was added dropwise, n-butyl lithium (59.3 ml of a 2.5M solution, 148 mmole), keeping the temperature below -20° C. The reaction was stirred at -20° C. for 1 hour, then cooled to -30° C. and cyclopentanecarboxylic acid (8.05 g, 7.65 ml, 70.6 mmole) added dropwise in a small amount of dry tetrahydrofuran. The reaction mixture was stirred at 0° C. for two hours, during which time a white precipitate formed. The solution was then cooled to -70° C., and a solution of 2-(dibenzylaminomethyl)-propenoic acid t-butyl ester (23.8 g, 70.6 mmol) in dry tetrahydrofuran (35 ml) was added dropwise. The reaction was left overnight (below -40° C.), and then poured into iced hydrochloric acid (4.2 eq, final pH=2) and the product extracted into diethyl ether. The ether layer was washed with hydrochloric acid, water (2×), dried (Na2SO4) and evaporated to yield the crude product (40 g). This was chromatographed over silica gel (500 g) eluting with dichloromethane containing methanol (0 to 5%) to yield, on evaporation of the pure fractions, 3-(1-carboxycyclopentyl)-2(dibenzylaminomethyl)propanoic acid t-butyl ester as an oil (18.3 g, 57%). Found: C,74 38; H,8.41; N,2 91. C28H37NO4 requires C,74.47; H,8.26; N,3.10%.
Workup
- additionwas added dropwise
- customthe temperature below -20° C
- temperaturecooled to -30° C.
- stirringThe reaction mixture was stirred at 0° C. for two hours, during which time a white precipitate
- customformed
- temperatureThe solution was then cooled to -70° C.
- waitThe reaction was left overnight (below -40° C.)
- extractionfinal pH=2) and the product extracted into diethyl ether
- washThe ether layer was washed with hydrochloric acid, water (2×)
- dry with materialdried (Na2SO4)
- customevaporated
- customto yield the crude product (40 g)
- customThis was chromatographed over silica gel (500 g)
- washeluting with dichloromethane
- additioncontaining methanol (0 to 5%)
Sources & evidence
- ORD record
- ord-d7bc0cd6185a4764ad998c826b692a62
- Source dataset
- uspto-grants-1990_10
- Patent number
- US04960792
Reaction notes
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