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

HRID 987115Notes

Reaction equation

HRID 987115 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-578a2524ed444e60aeb12455b4106c1b
Source dataset
uspto-grants-2003_10
Patent number
US06630512B2

Reaction notes

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