1- Methylnaphthalene, formylation

Substituted naphthalenes (acenaphthene, 2-methylnaphthalene) are also formylated by N,N-dialkylforinainides, but in low (20, 26%) yields. Generally speaking, several other methods of formylation and acylation exist in the organic synthesis repertoire. Nevertheless, the procedure described here is useful, for it uses inexpensive starting materials. 

TMLA is produced by tbe oxidation of one of the rings of the 2,6-di-methylnaphthalene molecule. 2-Formyl-6-naphthoic acid results from the incomplete oxidation of one of the methyl groups of the 2,6-dimethylna-phthalene molecule. ... 

Darzens reported that compounds of type 4 can be dehydrogenated to l-methyl-3-n hthoic acid 22 with the use of sulfur or selenium at elevated temperature. Subsequent decarboxylation using lime yielded 1-methylnaphthalen 23. This sequence of reaction can be carried out in one pot. Through a series of reactions the methyl naphthoic acid 22 can be converted to 4-methyl-2-naphthol 24, and further, with the aid of Vilsmeyer formylation to alkyl naphthofuran 25. ... 

Periasamy et at. obtained aldehydes in good yield from poly-cyclic aromatic hydrocarbon radical anions prepared by the addition of sodium to the aromatic hydrocarbon in THF, followed by formylation with carboxylic acid esters or N,N-dialkyformamides. Reactions of sodium naphthalenide, -anthracenide and -phenan-threnide with ethyl formate yielded the corresponding aldehydes. Substituted naphthalenes e.g. acenaphthene and 2-methylnaphthalene are also formylated using A/,A/-dialkylformamides, but in low yields (20% and 26% respectively). 

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