Phosphorus pentachloride → 4-chloro-2,2-dimethyl-3H-1,3-benzoxazine

HRID 842973Notes

Reaction equation

HRID 842973 reaction equation
[CH3:1][C:2]1([CH3:13])[NH:7][C:6](=O)[C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[O:3]1.P(Cl)(Cl)(Cl)(Cl)[Cl:15]>O=P(Cl)(Cl)Cl>[Cl:15][CH:6]1[C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[O:3][C:2]([CH3:13])([CH3:1])[NH:7]1

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 7174282,2-dimethyl-3,4-dihydro-2H-1,3-benzoxazin-4-one

Product 1

HCID 222447204-chloro-2,2-dimethyl-3H-1,3-benzoxazine

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A solution of 2,2-dimethyl-4-keto-1,3-benzoxazine (1.77 g, 10.0 mmol) and PCl5 (2.09 g, 10.0 mmol) in POCl3 (3.0 mL) was stirred at RT for 1 h then at 50-60° C. for 2 h. The reaction was concentrated and the product distilled (90-95° C./2-3 mm Hg) to afford 4-chloro-2,2-dimethyl-3H-1,3-benzoxazine. (0.496 g, 25%) as a clear oil: 1H NMR (CDCl3, 300 MHz, ppm) 7.58 (d, 1H), 7.48 (m, 1H), 6.97 (m, 1H), 6.94 (d, 1H), 1.63 (s, 6H).

Workup

  1. concentrationThe reaction was concentrated
  2. distillationthe product distilled (90-95° C./2-3 mm Hg)

Sources & evidence

ORD record
ord-640b89e489544dc585dcc3dd974e3b71
Source dataset
uspto-grants-2002_04
Patent number
US06376538B1

Reaction notes

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