Q. Fang, P. Grover, Z. Han
Aug 29, 2001
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0
Influential Citations
29
Citations
Journal
Tetrahedron-asymmetry
Abstract
Abstract ( S )-1,4-Benzodioxan-2-carboxypiperazine ( S )- 2 , the key chiral intermediate for the synthesis of ( S )-doxazosin, was prepared utilizing two approaches: (i) enzymatic resolution of ethyl 1,4-benzodioxan-2-carboxylate with an esterase ( Serratia ) followed by amide formation; (ii) direct resolution of 1,4-benzodioxan-2-carboxypiperazine 2 with d -tartaric acid. An efficient process for the conversion of ( S )- 2 to ( S )-doxazosin mesylate was developed (80% yield, 99.9% e.e.).