Ethyl bromoacetate → Acetic acid, (p-tolylsulfonyl)-, ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 5.0 g (15.5 mmol) of 6-methoxy-3-nitro-2-(toluene-4-sulfonyl methyl)-pyridine and 1.8 mL (16 mmol) of ethyl bromoacetate is dissolved in 20 mL of DMF. To this solution is added 4.4 g (32 mmol) of K2CO3 and the reaction mixture is heated to 50° C. for 18 hours. The reaction mixture is cooled to room temperature and diluted with 300 mL of water. The mixture is extracted with ethyl acetate. The ethyl acetate extracts are dried (Na2SO4) and evaporated to yield 7.2 grams of 6-methoxy-3-nitro-pyridin-2-yl]-[toluene-4-sulfonyl]-acetic acid ethyl ester. 1H NMR (CDCl3) δ 8.30 (d, 1H), 7.60 (d, 2H), 7.30 (d, 2H), 6.80 (d, 1H), 6.30 (m, 1H), 4.0 (q, 2H), 3.80 (s, 3H), 3.60 (m, 1H), 3.10 (m, 1H), 2.40 (s, 3H), 1.10 (t, 3H). Mass spectrum: m/e=409.0 (p+1). TLC (7/3: hexanes/ethyl acetate) Rf=0.5. Step 3:

Herkunft & Nachweise