Kyowa Hakko Kogyo Co., Ltd.

Toru Sugaya

Nobuhiro Nakamizo

Minoru Watanabe

Kenji Muto

Makoto Morimoto

Shiro Akinaga

Koji Yamada

Ikuo Matsukuma

Tokuyuki Kuroda

Yukiteru Mimura

Shinji Tomioka

Tamotsu Hashimoto

Yasushi Shida

Yutaka Osawa

Yoshinori Takemoto

Yukihiro Kuge

Takao Hatta

The present invention relates to a process for producing 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid compounds or salts thereof represented by the following formula (II): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 independently represent hydrogen, hydroxy or lower alkoxy, and R.sup.4 represent hydrogen, lower alkyl, aryl or aralkyl, the process comprising, allowing phenylalanine compounds to react with formaldehyde or paraformaldehyde in the presence of sulfuric acid or hydrobromic acid, the phenylalanine compounds being represented by the following formula (I): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the same meaning as defined above.

Process for producing tetrahydroisoquinoline-3-carboxylic acid compounds

Novel pyrazoloacridone compounds represented by the following formula: ##STR1## and pharmaceutically acceptable salts thereof have an excellent anti-tumor activity.

6H-pyrazolo-[4,5,1-d,e]acridin-6-one derivatives having anit-tumor

The compound of the formula ##STR1## is disclosed to have a less rapid decrease in blood pressure in its use as an antihypertensive.

1-benzyl-3,5-dimethyl-4-piperdyl ester of a Hantzsch dihydropyridine

Compounds having coronary and vasodilator effects, a hypotensive effect, and useful as antianginal drugs and drugs for treating hypertension are represented by the following general formula: ##STR1## wherein R.sub.1 and R.sub.2 are the same or different groups and each represents a lower alkyl group, one of R.sub.3 and R.sub.4 represents a lower alkyl group and the other represents a group of the general formula: ##STR2## wherein R.sub.5 represents an aralkyl group or an acyl group and n represents 0 or an integer of 1-3; the pharmaceutically acceptable acid addition salts thereof are also effective therapeutic compounds.

1,4-Dihydropyridine derivatives

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Nara, Japan

Toru Sugaya