Patents by Inventor John A. R. Mead

John A. R. Mead has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Production of N.sup.5 -methyltetrahydrohomofolic acid and related reduced derivatives of homofolic acid
    Patent number: 3983118
    Abstract: The preparation of N.sup.5 -methyltetrahydrohomofolic acid and alkali metal salts thereof is from homofolic acid starting material (HFA) by catalytic reduction with platinum oxide in the dark under hydrogen at a slight overpressure to produce tetrahydrohomofolate (THHF), them immediately reacting this product with formaldehyde to produce 5,11-methylenetetrahydrohomofolate and reducing this methylene intermediate without isolation with sodium borohydride to give the desired 5-methyltetrahydrohomofolate in the disodium salt form. The 5-methyl product is recovered by precipitating side products at a pH of about 3.8 with acetic acid and refrigerating the product filtrate overnight at about 3.degree.-10.degree.C. The filtrate containing the product 5-methyltetrahydrohomofolate (5-MeTHHF) is treated with charcoal, concentrated to an oil and the 5-methyl product is precipitated with absolute ethanol.
    Type: Grant
    Filed: August 16, 1974
    Date of Patent: September 28, 1976
    Assignee: The United States of America as represented by the Department of Health, Education and Welfare
    Inventors: Roger L. Knott, Alison Taunton-Rigby, John A. R. Mead