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

HRID 891045Notes

Reaction equation

HRID 891045 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-37ef25a31a3c4d5daf12ef02080277b9
Source dataset
uspto-grants-2006_02
Patent number
US07001921B1

Reaction notes

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