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Nouvelle methode de synthese des principaux metabolites des catecholamines marques au carbone 14
Author(s) -
Pichat Louis,
Tostain Jean
Publication year - 1977
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580130418
Subject(s) - chemistry , hydrogenolysis , sodium borohydride , acetic acid , vanillic acid , sodium hydroxide , yield (engineering) , benzoic acid , medicinal chemistry , stereochemistry , catalysis , organic chemistry , metallurgy , materials science
Methylsulfinylcarbanion used in large excess reacts with methyl (carboxyl 14 C) vanillate 2 a, methyl (carboxyl 14 C) isovanillate 2 b and methyl 3,4 dibenzyloxy (carboxyl 14 C) benzoate 2 d to give 90 % yields of β‐ketosulfoxides 3 a, 3 b, 3 d. Submitted to the acid catalyzed Pummerer rearrangement these β‐ketosulfoxides lead to the formation of methyl hemimercaptals of phenylglyoxals 4 a, 4 b, 4 d in good yields. These β‐keto‐α‐hydroxy sulfides react with sodium hydroxide to give respectively : 2–(4–hydroxy‐3‐methoxyphenyl)‐2‐hydroxy (2– 14 C) acetic acid 5 a (V.M.A.); 2–(3‐hydroxy‐4‐methoxyphenyl)‐2‐hydroxy (2– 14 C) acetic acid 5 b (iso V.M.A.) in overall yields of 55 % based on vanillic and iso‐vanillic acids; and 2–(3,4 dibenzyloxyphényl)‐2 hydroxy (2– 14 C) acetic acid 5 d, hydrogenolysis of which gave 2–(3,4 dihydroxyphenyl)‐2‐hydroxy (2– 14 C) acetic acid (D.H.M.A.) in 61 % overall yield from 3,4 dihydroxy benzoic acid. The β‐keto‐α‐hydroxysulfides 4 a, 4 b, 4 d reduced with sodium borohydride give respectively 2‐(4‐hydroxy‐3‐methoxyphenyl) (2– 14 C) ethyleneglycol (H.M.P.G.) 6 a; 2–(3‐hydroxy‐4‐methoxyphenyl) (2– 14 C) ethyleneglycol 6 b (iso H.M.P.G.) in overall yields of 64 % and 60 % based on vanillic and isovanillic acids; and glycol 6 d the hydrogenolysis of which gave 2–(3,4‐dihydroxyphenyl) (2– 14 C) ethyleneglycol 6 c (D.H.P.G.) in yield of 64 % based on 3,4 dihydroxybenzoic acid.