Reaktion #54303

Reaktionsgleichung

2,6-diethyl-4-nitrophenylisocyanate

sodium hydroxide

methylguanidine sulfate

HCl MeOH

sodium sulfate

→

1-(2,6-diethyl-4-nitrophenyl)-3-methylamidinourea hydrochloride

Lösungsmittel

methanol

water

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis added
2. 2
   workup.STIRRINGthe resulting mixture stirred at room temperature over-night
3. 3
   SonstigeThe tetrahydrofuran is removed under vacuum
4. 4
   Sonstigethe residue partitioned between water and chloroform
5. 5
   SonstigeThe layers are separated
6. 6
   Extraktionthe aqueous layer extracted with chloroform (1 × 100 ml)
7. 7
   TrocknenThe combined extracts are dried (MgSO4)
8. 8
   Einengenconcentrated
9. 9
   Sonstigeto give a yellow foam which
10. 10
    SonstigeThe methanol is removed under vacuum
11. 11
    Sonstigeto give a yellow viscous oil which
12. 12
    SonstigeCrystallization from methanol-ethyl acetate

Vorschrift

To a stirred suspension of 7.3 g (30.0 mmol) of methylguanidine sulfate in tetrahydrofuran (80 ml) is added 4.8 g (60.0 mmol) of 50% w/w sodium hydroxide in water with continued stirring for one hour. Anhydrous sodium sulfate (10.0 g) is added and the mixture stirred an additional hour after which 6.6 g (30.0 mmol) of 2,6-diethyl-4-nitrophenylisocyanate is added and the resulting mixture stirred at room temperature over-night. The tetrahydrofuran is removed under vacuum and the residue partitioned between water and chloroform. The layers are separated and the aqueous layer extracted with chloroform (1 × 100 ml). The combined extracts are dried (MgSO4) and concentrated to give a yellow foam which is dissolved in methanol and acidified with HCl/MeOH. The methanol is removed under vacuum to give a yellow viscous oil which solidifies on scratching. Crystallization from methanol-ethyl acetate gives 1-(2,6-diethyl-4-nitrophenyl)-3-methylamidinourea hydrochloride as a pale yellow solid, m.p. 173°-175° C.

Quelle