D-Cysteine → HCID 69602147, compound

Participants

Reaction Steps

(S)-2-(4′,5′-dimethoxyphenyl)-4-thiazoline-4-carboxylic acid (1) and (S)-2-(4′,5′-dimethoxyphenyl)-4-methylthiazoline-4-carboxylic acid (2) (also referred to as (S)-4′,5′-dimethoxydesazadesmethyldesferrithiocin and (S)-4′,5′-dimethoxydesazadesferrithiocin, respectively) were prepared starting with 2-benzyloxy-4,5-dimethoxybenzaldehyde (6), which was converted to the corresponding oxime by reacting 6 with hydroxylamine hydrochloride and triethylamine in acetonitrile at about 50° C. for about 18 hours. The corresponding nitrile (7) was prepared from the oxime by refluxing the intermediate product with phthalic anhydride for 1 day to give nitrile 7 in 87% yield. Nitrile 7 was reacted with hydrogen on a Pd—C catalyst in an ethanol/ethyl acetate mixture for about 50 minutes to remove the O-benzyl group and form 4,5-dimethoxy-2-hydroxybenzonitrile (8) in 84% yield. The deprotected nitrile 8 was subsequently reacted with D-cysteine or D-alpha-methylcysteine in a pH 6 buffer containing sodium bicarbonate and methanol to form products 1 and 2, respectively.

Provenance & Evidence