Methylhydrazine → HCID 178481944, compound

Temperature

24 °C

A flask was charged with 6 kg of ether and 6164.2 g (33.5 mol) of ethyl 4,4,4-trifluoroacetoacetate. With stirring 1542.4 g (33.5 mol) methylhydrazine was added. The temperature was maintained at about 24° C. during the addition. After one additional hour of stirring the reaction was complete. Solvent was stripped to remove most of the ether and the residue was then slurried in 12 1 of chloroform with vigorous stirring. To the slurry was added 50 ml of concentrated sulfuric acid and the mixture was stirred overnight. An additional 100 ml of sulfuric acid was added and the slurry was washed once with 3 1 of water and 5 times with 3 1 of 10% sodium bicarbonate to remove the 5-hydroxy isomer and twice with 3 1 of water. The aqueous layers and undissolved crystals were twice extracted sequentially with 4 1 of chloroform. Chloroform was stripped on a rotary evaporator at 40° C. under vacuum to yield 1405.9 g (25.3% yield) of a solid, m.p. 130°-131° C.

1. additionwas added
2. customto remove most of the ether
3. additionTo the slurry was added 50 ml of concentrated sulfuric acid
4. stirringthe mixture was stirred overnight
5. additionAn additional 100 ml of sulfuric acid was added
6. washthe slurry was washed once with 3 1 of water and 5 times with 3 1 of 10% sodium bicarbonate
7. customto remove the 5-hydroxy isomer
8. extractionThe aqueous layers and undissolved crystals were twice extracted sequentially with 4 1 of chloroform
9. customChloroform was stripped on a rotary evaporator at 40° C. under vacuum

ORD record

ord-597fabfe304e439fbd3f9228465404c4

Source dataset

uspto-grants-1989_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04855442