Methyl iodide → tert-Butyl (3-ethylpyridin-2-yl)carbamate

HRID 1625226Notes

Reaction equation

[CH2:1]([Li])CCC.[CH3:6][C:7]1[C:8]([NH:13][C:14](=[O:20])[O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[N:9][CH:10]=[CH:11][CH:12]=1.CI>C1COCC1>[CH2:6]([C:7]1[C:8]([NH:13][C:14](=[O:20])[O:15][C:16]([CH3:17])([CH3:19])[CH3:18])=[N:9][CH:10]=[CH:11][CH:12]=1)[CH3:1]

Participants

Conditions

Temperature: 0 °C

Procedure

Normal-butyllithium (2.69 M, 157.1 mL) was dropwise added to a solution of tert-butyl 3-methylpyridin-2-ylcarbamate (40.0 g) in THF (550 mL) at an internal temperature of −40 to −20° C., followed by stirring at 0° C. for 1 hr. Subsequently, a solution of methyl iodide (28.6 g) in THF (50 mL) was dropwise added to the reaction solution at an internal temperature of −70 to −60° C., followed by stirring at −78° C. for 30 min. The reaction solution was poured into ice water, followed by extraction with ethyl acetate twice. The organic layers were combined, washed with saturated saline, and dried over anhydrous sodium sulfate. The solvent was distilled away. Hexane (300 mL) was added to the resulting residue, and the precipitate was collected by filtration and dried under reduced pressure to obtain compound (40a) (32.4 g, 76%) as a white solid.

Workup

stirringby stirring at −78° C. for 30 min
extractionfollowed by extraction with ethyl acetate twice
washwashed with saturated saline
dry with materialdried over anhydrous sodium sulfate
distillationThe solvent was distilled away
additionHexane (300 mL) was added to the resulting residue
filtrationthe precipitate was collected by filtration
customdried under reduced pressure

Sources & evidence

ORD record: ord-7f98604f48f94df4b3d8608ebb01c520
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08779142B2

Reaction notes

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