Pyrithioxin prepn - neurotropic agent reducing blood-brain permeability to phosphate

摘要

Title cpd., bis-(2-methyl-3-hydroxy-4-hydroxymethyl-pyridin-5-yl-methyl) disulphide, is prepd. by reacting thiourea with a 2-methyl-3-hydroxy-4-hydroxymethyl-5-monohalomethyl-pyridine having protected OH gps. to recover S-(2-methyl-3-hydroxy-4-hydroxymethyl-pyridin-5-yl-methyl)isothio- urea with protected OH gps., hydrolysing this to remove the protecting gps. and oxidising the S-(2-methyl-3-hydroxy-4-hydroxymethyl-pyridin-5-yl-methyl)isothio- urea prod. with H2O2.