- 8 7 — 



Coumarin. A work by Ph. Chuit 1 ) and Fr. Boelsing supplies 

 a valuable contribution towards the knowledge of the coumarins alkylised 

 in the benzene nucleus, of which up to the present little was known. 

 In order to arrive at 3 -methyl coumarin 2 ), they condensed, according 

 to Kncevenagels 3 ) method, malonic acid with o-homosalicylic alde- 

 hyde, with application of aniline hydrochloride. The resulting product 

 of condensation, 3 -methyl coumarin carboxylic acid, forms white needles 

 of the melting point 142 to 143 . On distillation at ordinary pressure 

 it yields 3 -methyl coumarin of the boiling point 178 (20 mm. press.); 

 melting point 109 to no°. This body has a faint odour of coumarin. 

 3 -Methyl i-aceto coumarin forms odourless, faintly yellow crystals of 

 the melting point 125,8 to 126,2°. 



Its phenyl hydrazone melts at 168 to 169°, its semicarbazone 

 at 224 to 225°. 3 -Methyl coumarin carboxylic acid ester is formed 

 during the condensation of the above aldehyde with malonic acid 

 ester, with application of piperidine as condensing agent; odourless, 

 brilliant crystals of the melting point 8i°. 



The above-mentioned chemists proceeded in an entirely analogous 

 manner to produce the remaining homocoumarins and their derivatives. 

 Contrary to H. Schmidt 4 ), who obtained by Perkin's method from 

 m-homosalicylic aldehyde, by heating with acetic acid anhydride and 

 sodium acetate to 220°, a methyl coumarin melting at 90°, Chuit 

 and Bcelsing arrived at two different methylated coumarins. They 

 proved at the same time that Schmidt's preparation was a mixture of 

 two homocoumarins, whose formation could be thus explained, that 

 the m-homosalicylic aldehyde used for the condensation was a mixture 

 of two isomerides, methyl phenol-3-methylal-4 and methyl phenol-3- 

 methylal-2. The first aldehyde of the melting point 59° yields on 

 condensation with malonic acid, 4 - methyl coumarin - 1 - carboxylic acid 

 of the melting point 198,8 to 199,8°. The 4-methyl coumarin which 

 can be obtained from it, melts at 125,8° to 126,4°, an d has a fairly 

 strong odour of coumarin. The other m - homosalicylic aldehyde, 

 methyl phenol -3 -methylal-2, of the melting point 31,5°, condenses 



*) Bull. Soc. Chim. III. 35 (1906), 76. 



2 ) The coumarin formula is based on the designation of Simonis and Wenzel 

 (Berl. Berichte 33 [1905], 2327): — 



2 

 CH 



CHI 

 CO 



3 ) Berl. Berichte 31 (1898), 2585, 2696. 



4 ) Thesis, Rostock 1897. 



