GB519660A - Improvements in the manufacture of heterocyclic compounds of the diazaline series - Google Patents

Abstract

519,660. Diazalines. MORGAN, Sir G. T. and STEWART, J. Sept. 28, 1938, No. 28185. [Class 2 (iii)] Mono - nitro - 1:3 - diazalines are prepared by heating a dinitro-secondary amine of the general formula in a high boiling point medium' until nitrous fumes are evolved. ' The parent materials may conveniently be prepared by the method' described in Specification 461,185. High boiling media specified as suitable for use according to the present 'invention include nitrobenzene naphthalene and diphenyl. In examples (1) N - 21:41 - dinitro - phenyl - 2 - amino pyridine prepared by condensing 1-chloro-2:4-dinitrobenzene and 2-aminopyridine is mixed with an equal weight of naphthalene and boiled under reflux in a bath of molten metal. The product on extraction with hydrochloric acid is 1:3 pyrido - 7 - nitro - 4:5 benz - 1:3 diazaline. Instead of naphthalene, diphenyl may be used as the high boiling medium. The mononitro diazaline prepared as above is reduced catalytically by hydrogen under an initial pressure of 5 atmospheres in the presence of platinic oxide to the corresponding monoaminodiazaline. Reduction as above but using hydrogen under an initial pressure of 32 atmospheres results in the formation of tetrahydro-1:2-pyrido-7-amino- 4:5 benz-1:3 diazaline. The primary monoaminodiazaline on diazotization with nitrosylsulphuric acid in the presence of phosphoric acid followed by treatment of the diazo solution with alcohol gives 1:2-pyrido-4:5 benz-1:3 diazaline ; (2) N-2<1>-4<1>-dinitrophenyl-2-aminoquinoline prepared by refluxing 2-aminoquinoline and 1-chloro-2:4-dinitrobenzene in nitrobenzene solution is heated at 340‹-360‹C. under a pressure of 20 mm. Oxides of nitrogen are evolved and 1.2-quinolo-1-nitro-4:5-benz 1:3-diazaline sublimes. This material on catalytic reduction at 70‹C. under hydrogen at a pressure of 31 atmospheres in the presence of platinum oxide is converted into the corresponding aminodiazaline. The amino group is exchanged for hydrogen by the diazo reaction as in example (1) to give 1:2-quinolo-4:5-benz- 1:3-diazaline ; (3) N - 2<1>:4<1>- dinitrophenyl - 1- amino-isoquinoline prepared by refluxing I- aminoisoquinoline and 1-chloro : 2:4-dinitrobenzene in xylene solution is heated as in example (2) to give 1:2 (2<1>:1<1>) isoquinolo-7- nitro-4:5- benz-1:3-diazaline. This compound on catalytic reduction as in example (2) gives the corresponding monoaminodiazaline. The amino group is exchanged for hydrogen by the diazo reaction as in example (1) to give 1:2 isoquinolo-4:5 benz-1:3-diazaline ; (4) N-2':4'- dinitro-1<1>-naphthyl-2-aminopyridine prepared by refluxing 2-aminopyridine and 1-chloro-2:4- dinitronaphthalene in xylene solution is refluxed in nitrobenzene solution to form 1:2-pyrido-7- nitro-8:9-benzo-4:5 benz-1:3 diazaline. This is catalytically reduced as in example (1) to the corresponding monoaminodiazaline under a pressure of 5 atmospheres. At 31 atmospheres pressure nuclear hydrogenation takes place with the formation of tetrahydromonoaminobenzobenzdiazoline. The amino group is further exchanged for hydrogen by the diazo reaction as in example (1) ; (5) N-2<1>-4<1>-dinitro- 1<1>-naphthyl-2-aminoquinoline prepared by refluxing 2-aminoquinoline and 1-chloro-2:4- dinitronaphthalene in xylene solution is boiled under reflux in a molten metal both with twice its weight of diphenyl to give 1:2-quinolo-7- nitro-8:9-benzo-4:5 benz-1:3 diazaline. This is catalytically reduced as in example (1) to the corresponding monoaminodiazaline. The amino group is exchanged for hydrogen by the diazo reaction as in example (1); (6) N-2<1>:4<1>- dinitro - 1<1> -naphthyl - 1 - aminoisoquinoline prepared by refluxing 1-aminoisoquinoline and 1-chloro 2:4 dinitronaphthalene in xylene solution is heated on a molten metal bath in a mixed solution of nitrobenzene and phenol to form the corresponding nitrobenzobenzdiazaline. This compound is reduced catalytically with hydrogen under a pressure of 70 atmospheres to the monoaminobenzobenzdiazaline. This amino group is then exchanged for hydrogen by the diazo reaction as in example (1). Specification 496,258, also is referred to.