反応 #2286382

反応方程式

Iodomethane

Water

(2-bromo-4-methyl-thiazol-5-yl)-carbamic acid tert-butyl ester

NaH

→

desired product

収率 54.0%

(2-bromo-4-methyl-thiazol-5-yl)-methyl-carbamic acid tert-butyl ester

収率 54.0%

溶媒

ethyl acetate

DMF

反応条件

後処理

1. 1
   workup.STIRRINGstirred for 5 h
2. 2
   その他the resulting biphasic mixture was separated
3. 3
   抽出The aqueous layer was extracted one time with ethyl acetate
4. 4
   洗浄The combined organic extracts were washed twice with brine
5. 5
   乾燥dried over Na2SO4
6. 6
   ろ過filtered
7. 7
   濃縮concentrated to dryness under reduced pressure
8. 8
   その他The crude product was purified by silica gel chromatography (0-100% ethyl acetate/hexanes)

実験手順

To a solution of (2-bromo-4-methyl-thiazol-5-yl)-carbamic acid tert-butyl ester (2.93 g, 10 mmol) in DMF (50 mL) at 0° C. was added NaH (480 mg, 12 mmol, 60% dispersion in mineral oil) in one portion and the suspension was stirred for 1 h. Iodomethane (0.65 mL, 10.5 mmol) was added in one portion, and after 5 min the reaction mixture was warmed to ambient temperature and stirred for 5 h. Water and ethyl acetate were added and the resulting biphasic mixture was separated. The aqueous layer was extracted one time with ethyl acetate. The combined organic extracts were washed twice with brine, dried over Na2SO4, filtered and concentrated to dryness under reduced pressure. The crude product was purified by silica gel chromatography (0-100% ethyl acetate/hexanes) to give the desired product as a clear oil (1.66 g, 54%): IR (KBr) 1688 cm−1; 1H NMR (300 MHz, CDCl3) δ 2.98 (s, 3H), 2.29 (s, 3H), 1.54 (s, 9H); ESIMS m/z 309 (M+2).

出典