Mitsui Petrochemical Industries, Ltd.

Takeshi Ishitoku

Noriaki Kihara

Junichi Imuta

Teruaki Mukaiyama

Hiroaki Tan

Katsuya Takahashi

Daisuke Fukuoka

Takashi Tashiro

Naoya Sakamoto

Masaharu Ishiguro

Eiichiro Hata

Process for preparing polyalkyl-2-alkoxy-7-hydroxychroman derivative of the general formula (V): ##STR1## wherein R.sup.1 denotes lower primary alkyl, R.sup.2 denotes hydrogen or lower primary alkyl and R.sup.3 denotes loweralkyl, by reacting resorcin with either an aliphatic ketone of the general formula (I): ##STR2## wherein R.sup.1 and R.sup.2 are as defined above, and an alcohol of the formula (II):

Process for preparing polyalkyl-2-alkoxy-7-hydroxychroman derivatives

This invention concerns a method for the production of dimeric alkaloids, characterized by reacting of catharanthine with vindoline in the presence of Fe.sup.3+ and (1) removing or inactivating the Fe.sup.3+ and allowing the reaction product to react with a reducing agent or (2) allowing presence of oxygen and a dicarboxylic acid or a derivative thereof in the reaction system and allowing the reaction product to react with a hydride source. In accordance with this invention, such dimeric alkaloid as vinblastine, leurosidin, and 3',4'-anhydrovinblastine which are useful as antineoplastic drugs can be produced in high yields.

Method for production of dimeric alkaloids

A process for the purification of N-cyano-N'-methyl-N'-[2-{(5-methyl-1H-imidazol-4-yl)methylthio}-ethyl]guan idine, which comprises bringing a crude product of N-cyano-N'-methyl-N'-[2-{(5-methyl-1H-imidazol-4-yl)-methylthio}ethyl]guan idine into contact with activated carbon in water in the presence of an organic acid.

Process for purification of

A novel cyanoguanidine derivative represented by the following general formula (I): ##STR1## wherein X stands for a hydrogen atom, a chlorine atom or a bromine atom, and R stands for a lower alkyl group, is an effective precursor for the synthesis of N-cyano-N'-methyl-N'-(2-(5-methyl-4-imidazolylmethylthio(ethyl)-guanidine (Cimetidine) which has an action of controlling secretion of gastric acid and is valuable as an agent for the remedy of a gastric ulcer. This cyanoguanidine derivative is prepared by reacting a methylvinylketone derivative with a mercaptoguanidine derivative or by reacting an amidinoketone derivative with a halogenating agent.

Cyanoguanidine derivative and process for preparation thereof

Growing community of inventors

Yamaguchi, Japan

Takeshi Ishitoku