Yoshitomi Pharmaceutical Industries, Ltd.

Chiaki Kitami

Tsutomu Yamanaka

Mineo Tsuruda

Shinro Setoguchi

Takanori Oe

Gen Hasegawa

The present invention provides an industrially valuable method for preparing an optically active 3,4-dihydro-3,4-epoxy-2H-1-benzopyran compound which is useful as a starting material for an optically active benzopyran compound with antihypertensive, coronary blood flow-increasing activities and the like, and also provides a diastereometric ester compound with a 3-halo-4-hydroxy-2H-1-benzopyran compound which is useful as an intermediate for said epoxy compound.

Processes for preparing optically active

The present invention provides an industrially valuable method for preparing an optically active 3,4-dihydro-3,4-epoxy-2H-1-benzopyran compound which is useful as a starting material for an optically active benzopyran compound with antihypertensive, coronary blood flow-increasing activities and the like, and also provides a diastereomeric ester compound with a 3-halo-4-hydroxy-2H-1-benzopyran compound which is useful as an intermediate for said epoxy compound.

Piperazine compounds useful as analgesics, and having the formula: ##STR1## wherein each of R.sup.1 and R.sup.2 is hydrogen, halogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy or CF.sub.3 ; R.sup.3 is hydrogen, hydroxyl, an optionally substituted phenyl (e.g. phenyl, halo-phenyl, C.sub.1-4 alkyl-phenyl, C.sub.1-4 alkoxy-phenyl or CF.sub.3 -phenyl), pyridyl, 2-thienyl or 2-pyrimidinyl; m is 2 or 3; and n is 0, 1 or 2, and pharmaceutically acceptable acid addition salts thereof are disclosed.

Growing community of inventors

Mie, Japan

Chiaki Kitami