反应详情

温度

0 °C

To a solution of 4-pentylbenzoic acid (5 g, 0.026 mol) in 260 ml of CH2Cl2 containing molecular sieves (4 Å), two drops of DMF was added, and then oxalyl chloride (5.45 g, 0.043 mol) was added dropwise. After stirring for 4.5 h the mixture was filtered, concentrated on the rotatory evaporator and pumped for 15 min. The residue was redissolved in 130 ml of CH2Cl2 and N,O-dimethylhydroxylamine HCl (3.04 g, 0.031 mol) was added at room temperature. After cooling the solution to 0° C., 5.3 ml of pyridine (0.065 mol) was added and the solution was stirred at 23° C. for 18 h. The solution was concentrated on the rotatory evaporator and the residue was partitioned between brine and a mixture of ether and CH2Cl2 (1:1). The organic layer was separated, dried and concentrated to yield 5.9 g (98%) of 2, which was used without further purification in the subsequent step. 1H NMR (100 MHz, CDCl3) δ 0.9 (t, 3H), 1.45 (m, 6H), 2.6 (t, J=6.4 Hz, 2H), 3.3 (s, 3H), 3.5 (s, 3H), 7.2 (d, J=8.0 Hz, 2H), 7.6 (d, J=8.2 Hz, 2H).

1. filtrationwas filtered
2. concentrationconcentrated on the rotatory evaporator
3. waitpumped for 15 min
4. dissolutionThe residue was redissolved in 130 ml of CH2Cl2
5. stirringthe solution was stirred at 23° C. for 18 h
6. concentrationThe solution was concentrated on the rotatory evaporator
7. customthe residue was partitioned between brine
8. additiona mixture of ether and CH2Cl2 (1:1)
9. customThe organic layer was separated
10. customdried
11. concentrationconcentrated