Tejpal Singh Sodhi
Articles written in Proceedings – Section A
Volume 7 Issue 6 June 1938 pp 381-383
2: 4 Resorcylaldehyde undergoes condensation with malonic acid giving umbelliferon or umbellic acid according to the conditions. The yield is as expected lower than the lowest obtained with mono-hydroxybenzaldehydes.
A trace of pyridine gives better yield than any method, except that the yield is slightly higher when glacial acetic acid is used in place of a base.
Volume 9 Issue 6 June 1939 pp 511-517
Condensations of protocatechuicaldehyde, vanillin and veratraldehyde with malonic acid in the presence of various proportions of bases, and in the absence of any base, show that the hydroxy-group generally diminishes the yield, which rises when the group is methylated. Influences of different proportions of the base, and of different temperatures and periods of time at which the reactions are allowed to proceed are recorded. The trace of the base is generally as efficient as ever. The nitro-group on the other hand, when present on the nucleus, is not found to exert any restraining influence on the yields obtained, and allows very high yields of the nitro-cinnamic acids.