Methyl Anthranilate → 2-(2-aminophenyl)propan-2-ol
Reaction equation
[CH3:1][C:2]1([CH3:25])[C:7]2[CH:8]=[C:9](NC(=O)C3C=CN=CC=3)[C:10]([N+]([O-])=O)=[CH:11][C:6]=2[NH:5]C(=O)[O:3]1.C(OC)(=O)C1C(=CC=CC=1)N.C[Mg]I>>[NH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=1[C:2]([CH3:25])([CH3:1])[OH:3]Participants
Procedure
Thus, for example, 4,4-dimethyl-6-isonicotinoylamino-7-nitro-4H-3,1-benzoxazin-2-one is obtained by reacting methyl anthranilate with methyl magnesium iodide in ethereal solution to obtain o-aminophenyl-dimethylcarbinol, which is cyclised by reacting with phosgene in a mixture of toluene and chloroform as solvent in the presence of solid potassium carbonate to obtain 4,4-dimethyl-4H-3,1-benzoxazin-2-one. By subsequent nitration with fuming nitric acid (d=1.52), 4,4-dimethyl-6-nitro-benzoxazin-2-one is obtained which is converted by catalytic hydrogenation in the presence of Raney nickel in dimethyl formamide into 6-amino-4,4-dimethyl-4H-3,1-benzoxazin-2-one. By inserting an acetyl protecting group by means of acetic anhydride, the precondition for further nitration with fuming nitric acid (d=1.52) is created in the 7- position of the molecule. The acetyl protecting group is split off again from the resulting 6-acetamido-4,4-dimethyl-7-nitro-4H-3,1-benzoxazin-2-on e by treating with concentrated hydrochloric acid in isopropanol, and the resulting 6-amino-4,4-dimethyl-7-nitro-4H-3,1-benzoxazin-2-one is converted into 4,4-dimethyl-6-isonicotinoylamido-7-nitro-4H-3,1-benzoxazin-2-one by treating with isonicotic acid chloride in pyridine as solvent.
Sources & evidence
- ORD record
- ord-960971e2f03f42ea86561244d11dd10b
- Source dataset
- uspto-grants-1989_05
- Patent number
- US04831027
Reaction notes
Loading…