反应详情

A mixture of thionyl chloride (1.3 g, 0.011 mole) and 5,6-dihydro-3-methyl-1,4-dioxin-2-carboxylic acid (0.57 g, 0.004 mole) was refluxed on a steam bath for 3 hours and the excess thionyl chloride was evaporated at atmospheric pressure. The resulting liquid was added dropwise to a stirred solution of 1-methylethyl 5-amino-2-chlorobenzoate (1.6 g, 0.008 mole) in diethyl ether (30 ml), cooled in an ice-water bath. The mixture was worked up by diluting with diethyl ether (120 ml), washing with dilute hydrochloric acid (50 ml), and then with water (50 ml). The diethyl ether solution was dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure, leaving a solid residue. The crude product was washed with isopropyl alcohol (30 ml), leaving a brown solid, m.p. 103°-105° C. (1.2 g, 95.8% yield).

1. temperaturewas refluxed on a steam bath for 3 hours
2. customthe excess thionyl chloride was evaporated at atmospheric pressure
3. temperaturecooled in an ice-water bath
4. washwashing with dilute hydrochloric acid (50 ml)
5. dry with materialThe diethyl ether solution was dried over anhydrous sodium sulfate
6. filtrationfiltered
7. customevaporated under reduced pressure
8. customleaving a solid residue
9. washThe crude product was washed with isopropyl alcohol (30 ml)
10. customleaving a brown solid, m.p. 103°-105° C. (1.2 g, 95.8% yield)