反应详情

The methyl azodicarboxylate resin (4.0 g of 0.28 meq/g, ~1.1 meq) was suspended in THF (150 ml). A solution of benzoic acid (0.134 g, 1.1 mmol) in the THF (10 ml) was added. Ph3P (0.288 g, 1.1 mmol) and n-propanol (0.180 g, 0.22 ml, 3 mmol) in THF (7 ml) were added slowly at 25° C. and the mixture stirred for 26 hours. The resin was filtered and washed with CH2Cl2 (4×150 ml), and Et2O (2×100 ml). The yellow oil obtained on concentration of filtrate and washings was purified by flash chromatography (0.5% EtOAC in hexane) to yield to 55% of n-propyl benzoate. (Using dimethyl azodicarboxylate instead of the resin, a 56% yield was obtained). FT IR (neat) on the ester 1721, 1315 (m), 1276, 1111, 711cm-1 ; 1H NMR (80 MHz CDCl3) δ 0.98 (t, 3H, -CH2CH3), 1.75 (m, 2H, -CH2CH2CH3), 4.25 (t, 2H, --OCH2), 7.43 (t, 3H,) 8.30 (m, 2H) (Ph); EI--MS: 164.0836 (M+, 164.0838 calcd. for C10H12O2).

1. filtrationThe resin was filtered
2. washwashed with CH2Cl2 (4×150 ml), and Et2O (2×100 ml)
3. customThe yellow oil obtained on concentration of filtrate and washings
4. customwas purified by flash chromatography (0.5% EtOAC in hexane)