Ethyl hydrazinecarboxylate, from

Ethyl hydrazinecarboxylate, from hydrazine hydrate and diethyl carbonate, 51, 121 Ethyl 1-hydroxycyclohexylace-tate, 53, 67... 

Ethyl diazoacetate, as source of car-bethoxycarbene, 50, 94 Ethylene, with p-methoxyphenyl-acetyl chloride and aluminum chloride to give 6-methoxy- 3-tetralone, 51,109 Ethyl hydrazinecarboxylate, from hydrazine hydrate and diethyl carbonate, 51,121 Ethylidenecyclohexylamine, 50,66 Ethyl 1-iodopropionate, from ethyl... 

Diaminobiuret has been prepared only from N-tricarboxylic ester and hydrazine hydrate.1 Ethyl hydrazinecarboxylate has been prepared by reduction of nitrourethan electrolytically2 or with zinc dust and acetic acid,3 and by the action of hydrazine hydrate on diethyl carbonate,4 6 ethyl chlorocarbonate,6 and N-tricarboxylic ester.1... 

Phenyl-l-carbethoxysemicarbazide, from ethyl hydrazinecarboxylate and phenyl isocyanate, 51,122 with potassium hydroxide to give... 

A solution of 30 grams of ethyl hydrazinecarboxylate in 150 c.c, of water is added to 63 grams of freshly precipitated mercuric oxide suspended in 1 litre of water. A violent gas evolution soon takes place and heat is developed. The yellow colour of the mercuric oxide disappears, and the mass becomes dirty green. After the reaction subsides, the whole is left for several hours, then boiled and filtered. The residue is boiled up several times, with about 500 c.e. of water, and from the jfiltrate colourless needles separate on cooling. These are reerystaliised from much water or a little benzene... 

H2NNHCO2C2H5 + COj + 3 CjHsOH + NH3 product recovered by distillation. This triester reacts with hydrazine as in (2) to form two products. The first, diaminobiuret, is obtained as an ethanol-insoluble solid, m.p. 205° dec., in 69-75% yield. The second, ethyl hydrazinecarboxylate, is recovered from the filtrate by distillation and crystallized m.p. 52°, yield 90-95%. 

Kthyl hydrazinecarboxylate has been prepared from hydra-zinc hydrate and ethyl N-tricarboxylate in good yield.5 The method described here is comparable in efficiency but has the added advantage that both starting materials are commercially available. 

From in situ generated N -(3,3-dibromoacryloyl)hydrazinecarboxylic acid ethyl ester. The previously unreported 5-bromopyrazol-3-one 274 was prepared on a multigram scale by adaptation of standard literature procedures (04SL795) (Scheme 60). Thus, l,l,3,3-tetrabromopropan-2-one 268 underwent a Favorski rearrangement to 3,3-dibromopropanoic... 

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