From Aspirin to Piperonal
Hydrolysis of Aspirin
Merck 13th
Title: Aspirin
CAS Registry Number: 50-78-2
Properties: Monoclinic tablets or needle-like crystals. d 1.40. mp 135° (rapid heating); the melt solidifies at 118°. uv max (0.1N H2SO4): 229 nm (E1%1cm 484); (CHCl3): 277 nm (E1%1cm 68). Is odorless, but in moist air it is gradually hydrolyzed into salicylic and acetic acids and acquires the odor of acetic acid. Stable in dry air. pK (25°) 3.49. One gram dissolves in 300 ml water at 25°, in 100 ml water at 37°, in 5 ml alcohol, 17 ml chloroform, 10-15 ml ether. Less soluble in anhydr ether. Decomp by boiling water or when dissolved in solns of alkali hydroxides and carbonates. Inorganic salts of acetylsalicylic acid are soluble in water (esp the Ca salt, q.v.), but are decomposed quickly. LD50 orally in mice, rats: 1.1, 1.5 g/kg (Hart).
Reduction of Salicylic Acid
Ullmann`s
2-Hydroxybenzaldehyde can be produced by electrolytic reduction of salicylic acid on a rotating amalgam cathode [73] and by catalytic reduction of a salicylic acid halide [74].
[73] K. S. Udupa, G. S. Subramanian, H. V. K. Udupa, Ind. Chem. 39 (1963) 238 – 241;Chem. Abstr. 59 (1963) 10986 b.
[74] Seimi Kagakagu Co., JP 6813204, 1965 (S. Abe, K. Sato, T. Asami, T. Amakasu, T. Itakura); Chem. Abstr. 70 (1969) 28646 j.
Salicylaldehyde to Brenzcatechin
Organic Sntheses CV 1, 149
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV1P0149 (http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV1P0149)
To find the way from Brenzcatechin to Piperonal UTFSE
and
Post 480948 (https://www.thevespiary.org/talk/index.php?topic=11870.msg48094800#msg48094800)
(roger2003: "Preparation of Glyoxylic acid", Novel Discourse)
:)
From Aspirin to acetylsalicylaldehyde in a single elelectrolytical step (yield 30%)
Electrochem. Soc. 97, 183 (1950)
listet as ref. 222 in this overview
Post 438543 (https://www.thevespiary.org/talk/index.php?topic=12405.msg43854300#msg43854300)
(lugh: "Electroreduction Article", Serious Chemistry)
and from salicylic acid as ref. 79, 222, 351, 352