ChemicalBook CAS DataBase List 6-Fluoro-3,4-dihydro-2-oxiranyl-2H-1-benzopyran

6-Fluoro-3,4-dihydro-2-oxiranyl-2H-1-benzopyran synthesis

11synthesis methods

Product Name:6-Fluoro-3,4-dihydro-2-oxiranyl-2H-1-benzopyran
CAS Number:99199-90-3
Molecular formula:C11H11FO2
Molecular Weight:194.2

2H-1-Benzopyran-2-methanol, α-(chloromethyl)-6-fluoro-3,4-dihydro-

1017878-67-9
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6-Fluoro-3,4-dihydro-2-oxiranyl-2H-1-benzopyran

99199-90-3
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Yield:99199-90-3 96%

Reaction Conditions:

Stage #1: 2-chloro-1-(6-fluoro-3,4-dihydro-2H-1-benzopyran-2yl)ethanolwith sodium hydroxide in water;isopropyl alcohol at 0; for 1.5 h;Inert atmosphere;
Stage #2: with acetic acid in water;isopropyl alcohol;toluene;

Steps:

5 Synthesis of 6-fluoro-2-oxiranyl-1-benzopyran

Example 5 Synthesis of 6-fluoro-2-oxiranyl-1-benzopyran 2-Chloro-1-(6-fluoro-1-benzopyran-2-yl)-ethanol (2.5 g, 9.20 mmol, 84.9% A) was dissolved in i-PrOH (25 ml) under nitrogen and the reaction mixture cooled to 0° C. A 2M aqueous solution of NaOH (12.5 ml) was added to the solution over 5 min and the reaction was stirred for 1 hour 30 min. The reaction mixture was then diluted with toluene (50 ml) and the pH corrected with acetic acid (0.92 g). Toluene (50 ml) and demineralized water (10 ml) were then added to the mixture and the phases separated after extraction. The collected organic phases were then washed with demineralized water (50 ml). The toluene phase was then anhydrified by azeotropic distillation and concentrated until dryness in a rotary evaporator to give 6-Fluoro-2-oxiranyl-1-benzopyran as a mixture of diastereoisomers 52:48 (2.0 g, 96% yield, 86.1% A). Diast. RR,SS: δ_H (400 MHz; CDCl₃) 6.81-6.72 (3H, m), 3.88-3.82 (1H, m), 3.21-3.17 (1H, m), 2.89-2.76 (4H, m), 2.1-2.00 (1H, m), 1.97-1.87 (1H, m); Diast. SR,SR: δ_H (400 MHz; CDCl₃) 6.84-6.73 (3H, m), 3.87-3.81 (1H, m), 3.15-3.10 (1H, m), 2.91-2.78 (4H, m), 2.18-2.10 (1H, m), 1.96-1.84 (1H, m).

References:

US2011/237808,2011,A1 Location in patent:Page/Page column 5-6