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

HRID 1168209Notes

Reaction equation

HRID 1168209 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-4c3cd43becb44e6fb122cfb2c190228d
Source dataset
uspto-grants-2003_09
Patent number
US06624152B2

Reaction notes

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