Sodium nitrite in conversion of diethyl

Sodium a-naphthalenesulfonate, reaction with piperidine to form N-a-naphthyipiperidine, 40, 75 Sodium 0-naphthalenesulfonate, reaction with piperidine to form N-/3-naphthylpiperidine, 40, 74 Sodium nitrite in conversion of diethyl malonate to diethyl isonitroso-malonate, 40, 21... 

Sodium nitrite in conversion of diethyl malonate to diethyl isonitrosomalo-nate, 21... 

Diazotization of 2-aminopyrazine with nitrous acid in dilute or concentrated sulfuric acid gave 2 hydroxypyrazine (to 67% yield) (86, 477, 720, 818). Many such conversions have been described, mostly using nitrosylsulfuric acid in concentrated sulfuric acid solution. Preparations of hydroxypyrazines from the aminopyrazines are summarized as follows 2-hydroxy-3-methylpyrazine (sodium nitrite in concentrated sulfuric acid-acetic acid) (681), 2Jiydroxy-3,5-dimethylpyrazine (aqueous nitrous acid, then at 60°) (524), 3-hydroxy-2,5-dimethylpyrazine (477), 2,5-diethyl-3-hydroxypyrazine (aqueous nitrous acid) (478), 2-hydroxy-6-phenyl-pyrazine (365a), 24iydroxy-3,5-diphenylpyrazine (nitrous acid in N hydrochloric acid) (524), 3-hydroxy-2,5-diphenylpyrazine (282), 2-s-butyl-3-hydroxy-5-isobutyl-pyrazine (93), 5TS-butyl-3 hydroxy-2-isobutylpyrazine (92, 536), 2,5-di-s-butyl-3-hydroxypyrazine (89, 720), 3-hydroxy-2-isobutyl-5-isopropylpyrazine (103, 525), 2,3-dihydroxypyrazine (from 2 amino-3-hydroxypyrazine) (757, 1055) and its... 

The classical methods of conversion of a carboxy group into an amino group, the Curtius, Hofmann, and Schmidt reactions, have frequently been used to prepare amino-substituted organophosphorus compounds. Thus, the reaction of diethyl l-(ethoxycarbonyl)akylphosphonates with hydrazine gives the corresponding hydrazides, which, after treatment with sodium nitrite and EtOH and hydrolysis with concentrated HCl, are converted into oc-aminoalkylphosphonic acids in yields of 16-80%... 

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