Effects of 4-alkyl substitution on the photoreduction of benzophenone

Abstract

from light. The solution was cooled to 20°. Upon adjusting to pH 3 with concentrated hydrochloric acid, pteroic acid separated as a bright yellow solid. This was centrifuged at 3000 rpm and washed thoroughly by suspension and centrifugation with three to five 10-ml portions of water. The moist solid was freezedried to give 263 mg of pteroic acid (84%). The nmr spectrum in deuterated trifluoroacetic acid showed a singlet at 4.90 (2 H, bridge CH2), doublet at 7.49 (2 H, / = 9 cps, benzene CH), doublet at 7.85 (2 H, J = 9 cps, benzene CH), and a singlet at 8.54 (1 H, pteridine CH).