Sodium Bromide → Methyl 2-(bromoacetyl)pent-2-enoate
Reaction equation
[CH3:1][O:2][C:3](=[O:12])[C:4](=[CH:9][CH2:10][CH3:11])[C:5]([CH2:7]Cl)=[O:6].[Br-:13].[Na+]>CN(C)C=O>[CH3:1][O:2][C:3](=[O:12])[C:4](=[CH:9][CH2:10][CH3:11])[C:5]([CH2:7][Br:13])=[O:6]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 22 °C
Procedure
To a solution of 4-chloro-2-propylideneacetoacetic acid methyl ester (818 mg : 4.29 mMol.) in dimethylformamide (2.1 ml) is added sodium bromide (957 mg : 9.3 mMol.), and the mixture is stirred at 22° C. for 2 hours to give a solution of 4-bromo-2-propylideneacetoacetic acid methyl ester NMR δ (CDCl3) ppm:1.15(t. J=7.5Hz. 3H). Z.50(q, J=7.5Hz, 3H), 2.53(q, J=7.5Hz. 2H), 3.82(s, 3H), 3.90(s, 3H), 4.15(s, 2H). 4.Z2 (s, 2H), 7.10(t. J=7.5Hz, 1H), 7.1Z(t. J=7.5Hz. 1H)⟧ This solution is diluted with dichloromethane (0.7 ml), mixed with a solution of thiourea (354 mg : 4.65 mMol.) in dimethylformamide (1.4 ml), and stirred at -15° C. to 30° C. for 25 minutes. The reaction mixture is washed with aqueous sodium hydroxide and brine, concentrated at less than 15° C. under reduced pressure, mixed with acetone (1.8 ml), and neutralized with 35% hydrochloric acid. The separating crystals are washed with acetone and dried over to give (Z)-2-(2-aminothiazol-4-yl)-2-pentenoic acid methyl ester hydrochloride (452 mg). Yield: 43%. mp. 79 to 80° C. (decomposition). Elemental analysis gives values corresponding to C9H12N2O2S.HCl.H2O.
Sources & evidence
- ORD record
- ord-a8973ab17b6f41c582f0d2ded0302c9d
- Source dataset
- uspto-grants-1993_05
- Patent number
- US05214037
Reaction notes
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