Hydroxymethyl gramicidin antibiotic prodn. - by reacting formaldehyde dimethylacetal with gramicidin in acid alcoholic medium

摘要

Prepn. of hydroxymethyl gramicidin (I) comprises reacting the dimethylacetal of formaldehyde (II) with gramicidin in an acid alcoholic medium and pptg. (I) by adding a mineral or ammonium salt, pref. aq. NH4Cl. (II) is pref. in excess. The reaction is pref. carried out at room temp. The pH is pref. kept 5 by adding a mineral acid, e.G. H2SO4 or HCl. (I) is an antibiotic and is produced by better yield and purer from than by reaction of gramicidin with formaldehyde in ethanol. In an example, 6,000 g. gramicidin were dissolved in 120 l. 95% ethanol and 5 l. formaldehyde dimethylacetal added. NCHl was added to give pH 4-5. NH4Cl were added to ppte. (I) completely. Repptn. from 5% NH4Cl gave 5.950 g pure (I).