Method for preparing intermediate of adrenergic receptor agonist

Abstract

A method for preparing an intermediate of an adrenergic receptor agonist. The method comprises the following steps: cyclizing the compound of formula E1 or the compound of formula E2 and the compound of formula F0 to obtain the compound of formula C, where R1 is methyl, ethyl, isopropyl, propyl, tert-butyl, or butyl; R3 is H, Cl, F or Br; and L1 and L2 are each individually a leaving group. The method uses easily available raw materials, avoids the use of toxic and harmful reagents, is mild in terms of reaction conditions, is simple to operate, achieves a substantial improvement in yield and reduction in cost, and is more favorable for commercial production.

Dependencies are inferred from the claim text.