Ryozo Yamaguchi

Title: Ryozo Yamaguchi: Steroid Chemistry and Patent Contributions.

Introduction

Ryozo Yamaguchi is an inventor associated with Yokohama, Japan. His patent work includes processes for purifying steroid compounds and producing modified steroid intermediates. He is associated with Mitsubishi Chemical Industries Limited and is credited with 3 patents.

Latest Patents

Yamaguchi’s listed patents describe methods for improving the preparation and purification of steroid compounds.

“Process for the Purification of Steroids” describes purifying 19-norethisterone or 19-norandrost-4-ene-3,17-dione by passing a solution through a column packed with basic alumina, then crystallizing the purified compound. The solution uses an aromatic hydrocarbon, an alkyl halide, or an acetic acid ester as its solvent.

“Process for Producing 17-Acetals of 3-Alkoxyestra-2,5(10)-dien-17-ones” concerns producing steroid ketals from corresponding 3-alkoxyestra-1,3,5(10)-trien-17-one compounds. The process uses sodium or potassium, liquid ammonia, a tertiary alcohol, a hydrocarbon, and a cyclic ether solvent such as tetrahydrofuran, dioxane, or tetrahydropyran. The patent describes reaction conditions intended to improve yield and selectivity by forming two liquid phases, with the lower phase colored.

Career Highlights

Yamaguchi’s documented patent contributions focus on practical chemical processes in steroid synthesis and purification. His work addresses both the isolation of steroid compounds and the preparation of structurally modified intermediates. The supplied information associates his inventions with Mitsubishi Chemical Industries Limited.

Collaborations

Tadashi Oohama and Kunihiro Ninomiya are identified as Yamaguchi’s coworkers. The available information does not specify their roles in the listed patents.

Conclusion

Ryozo Yamaguchi’s patent record highlights process innovations in steroid chemistry, particularly purification and the production of steroid intermediates.