Diazomethane → Methyl 3-aminopicolinate
Reaction equation
[NH2:1][C:2]1[C:3]([C:8]([OH:10])=[O:9])=[N:4][CH:5]=[CH:6][CH:7]=1.[N+](=[CH2:13])=[N-]>CO>[NH2:1][C:2]1[C:3]([C:8]([O:10][CH3:13])=[O:9])=[N:4][CH:5]=[CH:6][CH:7]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
3-Aminopicolinic acid (115) (0.585 g, 4.24 mmol) was dissolved in MeOH (absolute, 45 mL). The solution was stirred while an ethereal solution of diazomethane was added until a yellow color persisted (~30 mL). The solution was stirred an additional 30 min, and the solvent rota-evaporated. The resulting residue was dried under reduced pressure at room temperature to yield 0.635 g (98.5%) of crude 116 as a yellow residue. The crude residue was chromatographed on a column of silica (12 g, Mallinckrodt, grade 62, mesh 60-200, used as received) using CHCl3 -MeOH [19:1, (180 mL), 7:3 (100 mL), 1:1 (100 mL), 100% MeOH (150 mL)]. After collecting appropriate fractions, rota-evaporating off the solvent and drying under reduced pressure at 25° C., 0.333 g (51.7%) of 116 was obtained as a yellow solid; mp 139°-146° C.; Rf =0.54 [CHCl3 -MeOH (9:1)]. IR (KBr) 3455, 3295, 3160, 1689, 1617, 1408, 1335, 1244, 1115. 1H NMR (CDCl3) δ3.98 (t, J=7.2, 3, CH3O--), 5.73 (d, J=1.8, 2, NH2), 7.05 (dd, J1 =1.2, J2 =8.4, 1, H-4), 7.22 (dd, J1 =4.2, J2 =8.4, 1, H-5), 8.07 (dd, J1 =1.2, J2 =4.2, 1, H-6).
Workup
- additionwas added until a yellow color
- customthe solvent rota-evaporated
- customThe resulting residue was dried under reduced pressure at room temperature
- customto yield 0.635 g (98.5%) of crude 116 as a yellow residue
- customThe crude residue was chromatographed on a column of silica (12 g, Mallinckrodt, grade 62, mesh 60-200, used as received)
- customAfter collecting appropriate fractions
- customrota-evaporating off the solvent
- customdrying under reduced pressure at 25° C.
Sources & evidence
- ORD record
- ord-3780749392094d31b630e521702c19c1
- Source dataset
- uspto-grants-1998_09
- Patent number
- US05801183
Reaction notes
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