Methanol → 4-(3-dimethylaminopropyl)-2-methyl-1H-pyrrole-3-carboxylic acid ethyl ester
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:10]([CH2:11][CH2:12][C:13](=O)[N:14]([CH3:16])[CH3:15])=[CH:9][NH:8][C:7]=1[CH3:18])=[O:5])[CH3:2].B.O1CCCC1.CO>O1CCCC1>[CH2:1]([O:3][C:4]([C:6]1[C:10]([CH2:11][CH2:12][CH2:13][N:14]([CH3:16])[CH3:15])=[CH:9][NH:8][C:7]=1[CH3:18])=[O:5])[CH3:2]Participants
Procedure
To a heterogeneous mixture of 4-(2-dimethylcarbamoyl-ethyl)-2-methyl-1H-pyrrole-3-carboxylic acid ethyl ester (1.01 g, 4 mmol) in tetrahydrofuran (9 mL) was added dropwise 8 mL of borane-tetrahydrofuran complex (1M solution in tetrahydrofuran). The mixture was heated to reflux overnight. Nine mL of methanol was added slowly to the reaction and the heating was continued for another 2 hours. The cooled reaction was quenched with 1 N hydrochloric acid and extracted with ethyl acetate. The aqueous layer was basified with aqueous potassium hydroxide, extracted with ethyl acetate, and the organic layer washed with brine, dried and concentrated to give 616 mg (65% yield) of 4-(3-dimethylamino-propyl)-2-methyl-1H-pyrrole-3-carboxylic acid ethyl ester as a faint orange oil. 1H-NMR (360 MHz, dimethylsulfoxide-d6) δ 10.84 (br s, 1H, NH), 6.36 (d, 1H), 4.12 (q, 2H, OCH2), 2.52 (m, 2H, CH2), 2.34 (s, 3H, CH3), 2.17 (m, 2H, CH2), 2.08 (s, 6H, N(CH3)2), 1.57 (m, 2H, CH2), 1.23 (t, 3H, CH3).
Workup
- temperatureThe mixture was heated
- temperatureto reflux overnight
- customThe cooled reaction
- customwas quenched with 1 N hydrochloric acid
- extractionextracted with ethyl acetate
- extractionextracted with ethyl acetate
- washthe organic layer washed with brine
- customdried
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-b09f7289a8b147fa8f076032cf19f703
- Source dataset
- uspto-grants-2007_01
- Patent number
- US07157577B2
Reaction notes
Loading…