— 88 — 



with malonic acid to 6-methyl coumarin- 1 -carboxylic acid of the melting 

 point 162,5 to 163 . The 6-methyl coumarin corresponding to it has 

 the melting point 65 to 65,8°. It possesses only a feeble coumarin 

 odour. The two methyl coumarins produced by the authors according 

 to Per kin's method, show the same melting point, which disproves 

 Schmidt's observation. The 4 -methyl coumarin- 1 -carboxylic acid ester 

 which can be derived from the methyl phenol-3~methylal-4, and which 

 is obtained in a manner analogous to the method described above, 

 forms brilliant leaflets, which melt between 101,5 and 102,5°. 4-methyl- 

 i-aceto coumarin of the melting point 156 to 1 57° yields an oxime which 

 melts at 224°. The other carboxylic acid ester which is derived from 

 methyl phenol - 3 - methylal - 2 , forms brilliant needles of the melting 

 point 122 to 122,5°. 6 - methyl- 1 - aceto coumarin shows the melting 

 point 115°, its oxime that of 214°. 



The condensation of p-homosalicylic aldehyde (methyl phenol-4- 

 methylal-3) with -malonic acid leads to 5 -methyl coumarin carboxylic 

 acid of the melting point 166,8°. Its ester forms odourless, trans- 

 parent tablets of the melting point 103 to 104°. 5 -methyl coumarin 

 has, of all the homocoumarins described, the most powerful odour, but 

 it differs slightly in the odour from ordinary coumarin. The latter is 

 more penetrating, but not so persistent as the former. In view of the 

 high price of p-homosalicylic aldehyde, or p-cresol, 5 -methyl coumarin 

 appears hardly capable of competing with ordinary coumarin. 5 -methyl 

 coumarin boils at 14 mm. pressure at 174°, and melts at 74,6 to 75°. 

 Its acetyl derivative of the melting point 128 to 128,4°, is obtained in 

 a manner analogous to the former; semicarbazone melting point 2 1 1 ° ; 

 oxime melting point 219°; phenyl hydrazone melting point 193 to 194°. 



The same authors 1 ) have subsequently published the results of 

 their examination of the two above-mentioned m - homosalicy lie alde- 

 hydes. A separation of these bodies, produced, according to the 

 method of Tiemann and Schotten 2 ), by the action of chloroform 

 on m-cresol, can be effected by repeated treatment of the aldehyde 

 mixture with small quantities of dilute soda liquor, when only the 

 aldehyde of the melting point 59° is dissolved. Another method of 

 separation is based on the different solubilities of their calcium salts 

 in hot water. The calcium salt of methyl phenol-3 -methylal- 2 of the 

 melting point 32° dissolves with difficulty, and is precipitated in the 

 form of yellowish crystals, when a hot dilute solution of calcium 

 chloride is added to the hot soda liquor solution of the aldehyde 

 mixture, whilst the salt of the methyl phenol-3 -methylal-4 melting at 59° 

 remains in solution in the mother-liquor and only separates out on cooling. 



*) Bull. Soc. Chim. III. 35 (1906), 129. 

 2 ) Berl. Berichte 11 (1878), 773. 



