[PAGE 1]
I received -today a bottle labeled 9-Amino-l,2 3,4-tetrahydroacridine. On checking my stock I find that I have 5 grams of the material which was obtained in October through Dr. Ray Shelton, William S. Merrell & Co.,and which is labeled tetrahydroaminoacrine.

This presumably is the same material as that used by Samuel Gershon ("Blocking effect of tetrahydroamincacrine on a new psychotomimetic agent," Nature 186: 1072-1073, June25, 1960). In that article tetrahydroaminoacrine is designated 1,2,3,4- Tetrahydro-5-aminoacridine.The structural formula given in the article however is identical with the structural formula on the bottle I received from the Applications Development Company. I presume that both the compound I received from Merrell & Co. and the one you sent me are the same, and that the difference in naming is due to some differences in the conventions for numbering the ring system. However, would you please have the chemist check this for me?

Dr. Utterback spent yesterday and today with us. I have tried to impart to him my philosophy about clinical testing of new drugs, including the necessity for measuring things, establishing the reproducibility of the measurements made, doing dose-effect curves, and making proper statistical designs.

Kindest regards,

Harris Isbell, M.D. Director

HI:rn

B-378

4.

228

Na lda a Meata Besic Addktieg Raupeh Crate U.5, Futic Sasità Service Mospitai Lezisgooa, Lenacty

DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

PUBLIC HEALTH SERVICE 21 March 1962