Citric acid prepn. from 3-methylene-pentane-1,5-diol - by nitrating with di:nitrogen tri:oxide in nitric acid at low temp. and heating

摘要

Citric acid is prepd. by (a) treating 3-methylene-pentanediol-1.5 (I), with a soln. of 0.5-1 mol. N2O3 in 10-20 mol. 50-70wt. % HNO3, both mol. quantities referring to 1 mol. (I) at -10 to +10 degrees C, for a short time; then (b) heating the mixt. to 35-60 degrees C, until oxidn. to citric acid is completed and recovering the citric acid after HNO3 sepn. Citric aicd yield and purity are increased. Quantity of waste gas, consisting mainly of N2, is reduced.