4-Chloro-6-hydrazinopyrimidine

A solution of 22 4, 6-Dichloropyrimidine (15g, 100mmol) in 23 ethanol was cooled to 0–5°C in 250mL three-necked flask. To the above flask 24 Hydrazine hydrate (4.7mL, 120mmol) was added dropwise under cooling atmosphere. After that, the reaction mixture was stirred for 90min at room temperature. Reaction progress was checked on TLC and poured into water to get crude product. Pure 4-chloro-6-hydrazinylpyrimidine (A) as Pale yellow solids [47] obtained by recrystallization in ethanol. Yield 95percent; Yellowish white solid; Rf=0.5 (hexane:ethyl acetate, 4:1); m.p. 164°C, A mixture of 4, 6-dichloro-pyrimidine (18.68 g, 125 mmol), hydrazine monohydrate (18.28 mL, 376 mmol), and 2-propanol (300 mL) was stirred at room temperature for 3 hours. The reaction mixture was concentrated, triturated with water, and filtered. The solid was washed with water, air-dried to give (6-chloro-pyrimidin-4-yl)- hydrazine (16.97 g, Yield 94percent): A mixture of 4, 6-dichloro-pyrimidine (18.68 g, 125 mmol), hydrazine monohydrate (18.28 mL, 376 mmol), and 2-propanol (300 mL) was stirred at room temperature for 3 hours. The reaction mixture was concentrated, triturated with water, and filtered. The solid was washed with water, air-dried to give (6-chloro-pyrimidin-4-yl)- hydrazine (16.97 g, Yield 94percent): 11.8 ml (12.1 g, 241.6 mmol) hydrazine hydrate are added dropwise to a solution of 20.0 g (134.3 mmol) 4, 6-dichloropyrimidine in ethanol at RT, while stirring. If clouding of the solution occurs during metering in of the hydrazine hydrate, further ethanol (approx. 400 ml) is added. The reaction solution is subsequently stirred at RT for 12 h. For working up, the solid which has precipitated out is filtered off, the residue on the filter is washed twice with 150 ml water each time and twice with 100 ml diethyl ether each time and the product is dried in vacuo. A further crystalline product fraction is obtained from the concentrated mother liquor.Yield: 16.8 g (87percent of th.)LC-MS (Method 1): RWith stirring and at RT, 11.8 ml (12.1 g, 241.6 mmol) of hydrazine hydrate are added dropwise to a solution of 20.0 g (134.3 mmol) of 4, 6-dichloropyrimidine in 300 ml of ethanol. If the solution becomes turbid during the addition of the hydrazine hydrate, more solvent (about 400 ml of ethanol) is added. The reaction solution is stirred at RT for a further 12 h. For work-up, the precipitated solid is filtered off, the filter residue is washed twice with in each case 150 ml of water and twice with in each case 100 ml of diethyl ether and the product is dried under reduced pressure. A further crystalline fraction is obtained from the concentrated mother liquor.Yield: 16.8 g (87percent of theory)LC-MS (Method 1): R

Molecular Weight:144.56
XLogP3:0.7
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:144.0202739
Monoisotopic Mass:144.0202739
Topological Polar Surface Area:63.8
Heavy Atom Count:9
Complexity:88.6
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes