1,1 -dichloro-3,5-dioxo-4-isopropyl

Dichloro-3,5-dioxo-4-isopropyl-2-methyl- E12b, 536 (H3C-CO-A-CO-CH2-R + TeCl4)... 

Methyl 2,3-diamino-6-methylbenzoate gave methyl 6-methyl-2,3-dioxo-l,2,3,4-tetrahydro-5-quinoxalinecarboxylate (252) [(C02H)2,4M HCl, reflux, 90 min 69% note survival of the ester grouping]. 2,3-Diamino-5,6-dichlorotoluene gave 6,7-dichloro-5-methyl-2,3(l//,4//)-quinoxalinedione (253) [(C02H)2, 4M HCl, reflux, 6 h 66%], 2-Isopropylaminoaniline gave l-isopropyl-2,3(l//,4//)-quinoxalinedione (254)... 

The following alkoxypyrazines have been prepared from the corresponding dichloropyrazines and alkoxide ions 2,3-dimethoxy-5,6-dimethyl(and diphenyl) (797) 2,3-dibenzyloxy (sodium benzyl oxide in benzyl alcohol at reflux for 24 hours (883)] [but 23-dichloropyrazine with sodium hydride and benzyl alcohol in xylene gave l,4-dibenzyl-2,3-dioxo-l,2,3,4-tetrahydropyrazine)(988)] 2-chloro-5-methoxy (838) 2,5-diethoxy-3,6-dimethyl (872) 2methanolic sodium methoxide refluxed for 2 h) 2,5-dimethoxy-3-phenyl (817) 2-chloro-5-methoxy(and ethoxy)-3,6-diphenyl (817) 2,5-dimethoxy-3,6-dimethyl (and diisopropyl) (844) 2,5-dimethoxy-3-isopropyl-6-methyl (methanolic potassium methoxide at reflux for 6 days) (844) 2(5)-s-butyl-3-chloro-6-ethoxy-5(2)-isobutyl (93) 2-chloro-6-methoxy (838, 883) 2,6-dimethoxy (reflux for 8h) (832) 2,6-diethoxy (reflux for 14 h) (883) 2-benzyloxy-6-chloro (1 equiv. of sodium hydride and benzyl alcohol in benzene at reflux) (832) 2,6-dibenzyloxy (5 equiv. of sodium benzyloxide in benzene at reflux gave 70%) (832) and 3,5-dimethoxy-2-methyl (535). 

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