| 摘要 |
NEW MATERIAL:The compound of formula (R is 2-12C alkyl). EXAMPLE:2-(1-Propionyloxy-4-methl-3-penten-1-yl)-5,8-dihydroxy-1,4-nap htho quinone. USE:An antithrombotic agent. PREPARATION:The compound of formula can be prepared by reacting shikonin with an acid halide at a molar ratio of 1:1-5 in the presence of a molecular sieve using ethyl acetate, etc. as the solvent. The molecular sieve is e.g. the type of 4A, 5A, 13X, etc. having the pore size to absorb HCl but do not absorb shikonin, and its amount is 0.5-5g per 1g of shikonin.
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