Hydrochloric Acid → 2-(Pyridin-2-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole-3-carboxylic Acid
Reaction equation
[O-]CC.[Na+].C1(C)C=CC=CC=1.C([O:14][C:15](=[O:31])[CH2:16][C:17](=[N:24][N:25]1[CH2:29][CH2:28][CH2:27][C:26]1=O)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][N:19]=1)C.Cl>O>[N:19]1[CH:20]=[CH:21][CH:22]=[CH:23][C:18]=1[C:17]1[C:16]([C:15]([OH:14])=[O:31])=[C:29]2[CH2:28][CH2:27][CH2:26][N:25]2[N:24]=1Participants
6
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 100 °C
Procedure
Add sodium ethoxide (145 g, 2.03 mol), followed by toluene (7 L) and 3-(2-oxo-pyrrolidin-1-ylimino)-3-pyridin-2-yl-propionic acid ethyl ester (Preparation 3-B; 280 g, 1.02 mol) to a 22 L flask equipped with mechanical stirrer, nitrogen inlet and a reflux condenser. Heat the mixture to 100° C. for 21 h. Cool to room temperature, add water (6 L), and adjust to pH 5 with concentrated hydrochloric acid. Separate the organic layer and extract the aqueous layer with 10% isopropyl alcohol in chloroform (2×9 L). Combine the organic layers, dry (sodium sulfate), filter, and concentrate in vacuo to yield 218 g (93%) of the title compound as a yellow solid MS ES+ m/e 230 (M+1).
Workup
- customequipped with mechanical stirrer, nitrogen inlet and a reflux condenser
- temperatureCool to room temperature
- customSeparate the organic layer
- extractionextract the aqueous layer with 10% isopropyl alcohol in chloroform (2×9 L)
- dry with materialCombine the organic layers, dry (sodium sulfate)
- filtrationfilter
- concentrationconcentrate in vacuo
Sources & evidence
- ORD record
- ord-7f5a5cf2dc49467788438b113c4d38e9
- Source dataset
- uspto-grants-2008_05
- Patent number
- US07368445B2
Reaction notes
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