Ethanol → 7-(Benzylamino)-4-methyl-2H-1-benzopyran-2-one

Participants

Reaction Steps

7-Benzylamino-4-methylcoumarin was synthesized from 3-benzylaminophenol and ethyl acetoacetate by the usual Peckmann reaction (anhydrous zinc chloride, absolute ethanol). Recrystallization from ethanol gave flat needles, m.p. 174.5°-175.5° C. The fluorescence maximum in water was 455 nm (excited 355 nm), in 10-2N HCl 458 nm. 1H nmr (60 MHz, CDCl3), δ2.36 (s, 3H, C--CH3), 4.45 (d, 2H, --CH2NH--, J=~5.5 Hz, collapses to a singlet when D2O added), 4.7-5 (1H, NH), 6.03 (s, 1H, H3), 6.57 (d, 1H H8), 6.63 (dd, 1H, H6, J56 =~9 Hz, J68 =~2 Hz), 7.45 (s, 5H, C6H5), 7.45 (d, 1H, H5, J56 =~9 Hz).

Provenance & Evidence