Oxydation und Nitrierung von Dimethyl‐naphthalinen

Abstract

Die Einwirkung von siedender Salpetersäure verschiedener Konzentration auf 1.6‐, 1.7‐, 2.3‐, 2.6‐ und 2.7‐Dimethyl‐naphthalin liefert 1‐Nitro‐2‐methylnaphthoesäuren und 1.8‐Dinitro‐dimethyl‐naphthaline. Mit sinkender Salpetersäurekonzentration nimmt der Anteil der Dinitrokohlenwasserstoffe an der Gesamtausbeute ab, derjenige der Nitrosäuren zu. Die Konstitution der Produkte wird bewiesen. Ähnlich wie die elektrophile aromatische Substitution hängt die Oxydationsfähigkeit der Methylseitenkette von der Elektronendichte am substituierten Ringkohlenstoffatom ab.

Preparation of a range of NNN′N′-tetrasubstituted 1,8-diaminonaphthalenes

“…Thus the transition state that should lead to (23) is destabilised and so cyclisation preferentially occurs onto the same nitrogen atom. The methyl groups on the carbon bridge presumably produce the isopropyl group in (24) by ring opening and hydride transfer followed by ring closure. In an alternative pathway, the bridge is completely removed and reaction with a second molecule of the xylene then gives the The procedure for extraction of the amines was the same in all cases except for compound (5) as stated.…”

“…1,8-Bis(dimethylamino)-2.7-dimethoxynaphthalene (1 6) and 1,8-bis(diethylarnino)-2,7dimethoxynaphthalene (1 7) are similarly prepared by reduction and alkylation of 1,8-dinitr0-2,7-dimethoxynaphthalene. Reaction of 2,2-dimethyl-l,3-dihydroperimidine with aa'-dibromo-o-xylene led, surprisingly, to (1 2) and 5-(2-propyl) (24). SINCE our demonstration in 1968 of the remarkable basicity of l,S-bis(dimethylamino)naphthalene,l there has been continuing interest in this and related comp o u n d~.~-~~, ?…”

“…Reaction of 2,2-dimethyl-l,3-dihydroperimidine with aa'-dibromo-o-xylene led, surprisingly, to (1 2) and 5-(2-propyl) benzo[g]naphtho[l,8-bc]-l,5-diazabicyclo[4. 3.O]nonane (24).…”