Methylhydrazine, reaction with dimethyl

The anhydrides 1 and 10 were converted into derivatives of l,3,4-thiadiazolo[2,3-6]quinazoline 284 in three stages, i.e., reaction with hydrazine or methylhydrazine, cyclization of the obtained hydrazides 285 to compounds 286 (by the action of KOH and CS2), and reaction of the latter with dimethyl acetylenedicarboxylate [182],... 

Chemical Reactions. It burns with a luminous flame and is readily expld (Ref 2). It is reduced with Zn dust and Na hydroxide to dimethyl hydrazine (Ref 2). Action of coned HC1 forms methylhydrazine and formaldehyde (Ref 2). Treatment in anhyd eth with Na metal forms a solid adduct which gives dimethylhydrazine on addn of w (Ref 4). For a review of thermal and photochem reactions see Ref 8 Explosive Limits. In mixts with air the crit press at which exp] occurs varies inversely with temp betw 350 and 380° (Ref 6)... 

Pyrazoles.—Formation. Butadiyne reacts with methylhydrazine to yield either 1,3-dimethylpyrazole (407) or the 1,5-isomer, depending on conditions. 2,2-Diacylketen 55-dimethyl acetals and related compounds yield methylthio-pyr-azoles on treatment with hydrazine thus compound (408) gives the ketone (409), ° and the nitrile (410) gives the amine (411), The azine (412) is converted into the pyrazole (413) in refluxing xylene the reaction involves... 

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