反应详情

Step 81) A THF solution (50 mL) of 1-hydroxy-cyclopropanecarboxylic acid ethyl ester (5 g, 38.4 mmol) and pyridine (3.3 mL, 41 mmol) was added dropwise a phosgen/toleune solution (25 mL, 47.5 mmol) at 0° C. in 5-10 min. the reaction mixture was allowed slowly warm up overnite. The solid was filtered off and the filtration was concentrated in vacuo. The residue was dissolved in hexane, refiltered, and concentrated in vacuo to afford.7.4 g (100%) the product. The product was dissolved in CH2Cl2 (100 mL) as a stack solution: 1H NMR (300 MHz, CHLOROFORM-D) □ ppm 1.25 (t, J=7.14 Hz, 3H), 1.37 (m, 2H), 1.57 (m, 2H), 4.21 (q, J=6.95 Hz, 2H); (ppm) 13.97, 15.75, 62.07, 62.13, 150.54, 168.71.

1. temperaturewas allowed slowly warm up overnite
2. filtrationThe solid was filtered off
3. filtrationthe filtration
4. concentrationwas concentrated in vacuo
5. dissolutionThe residue was dissolved in hexane
6. concentrationconcentrated in vacuo
7. customto afford