2-hydroxybenzamide

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Salicylamide (6.85 g, 50 mmol) and 4-acetoxybenzoyl chloride (10.9 g, 55 mmol) were dissolved in 35 mL anhydrous xylene. Anhydrous pyridine (0.5 mL) was added and the reaction mixture was refluxed under nitrogen for 12 h. Water was removed by a Dean-Stark apparatus. The mixture was cooled to rt, and the xylene was removed under vacuum. Acetone (100 mL) was added and the mixture was stirred for 10 min. The solid was filtered off, washed with acetone and dried under vacuum to give the crude compound (3.0 g). The crude compound (1.5 g) was purified by column chromatography (SilicaGel 70-230 mesh; 2-5% MeOH in DCM as eluent) to give 770 mg of 2-(4-hydroxyphenyl)benzo[e][1,3]oxazin-4-one (12%) as pale yellow solid. MS (ES) m/z: 240.02; Mp. 273-275° C. the reaction mixture was refluxed under nitrogen for 12 h Water was removed by a Dean-Stark apparatus the xylene was removed under vacuum Acetone (100 mL) was added The solid was filtered off washed with acetone dried under vacuum to give the crude compound (3.0 g) The crude compound (1.5 g) was purified by column chromatography (SilicaGel 70-230 mesh; 2-5% MeOH in DCM as eluent)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of salicylamide (4.14 g, 30.2 mmol) and conc. sulfuric acid (3 drops) in acetone (40 mL) was refluxed for 5 h. The reaction was concentrated and the residue taken up in ethyl acetate. The organic solution was washed with 1 N NaOH (2×), 1 N HCl (2×), H2O, then sat. aq. NaCl, dried (MgSO4) and concentrated to afford 2,2-dimethyl-4-keto-1,3-benzoxazine (2.50 g, 47%) as a white solid: 1H NMR (CDCl3, 300 MHz, ppm) 7.92 (d, 1H), 7.60 (bs, 1H), 7.47 (m, 1H), 7.06 (m, 1H), 6.92 (d, 1H), 1.65 (s, 6H). The reaction was concentrated The organic solution was washed with 1 N NaOH (2×), 1 N HCl (2×), H2O sat. aq. NaCl, dried (MgSO4) concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of polyphosphonate ethyl ester (PPE) (3.46 g, 8.0 mmol) in chloroform (10 mL) was added salicylamide (548 mg, 4.0 mmol) followed by addition of a solution of (±)-Methyl 2-ethoxy-3-[4-[(2,2-diethoxy)ethoxy]phenyl]propanoate (1.28 g, 4.4 mmol) obtained in preparation 2, in chloroform (10 mL) dropwise at 25-30° C. The reaction mixture was immersed in a preheated oil bath at 70° C. and refluxed 12 h. The reaction mixture was cooled to room temperature and CHCl3 was removed under reduced pressure. The resultant residue was neutralised (pH=7.0) with saturated aqueous NaHCO3 solution and extracted with ethyl acetate (3×20 mL). The combined organic extracts were washed with brine, dried over anhydrous Na2SO4 and concentrated. The crude compound was chromatographed on silica gel using a gradient of 5-25% of ethyl acetate in pet ether as eluent to afford the title compound (1.15 g, 72%) as a pale yellow liquid. The reaction mixture was immersed in a preheated oil bath at 70° C. refluxed 12 h CHCl3 was removed under reduced pressure extracted with ethyl acetate (3×20 mL) The combined organic extracts were washed with brine dried over anhydrous Na2SO4 concentrated The crude compound was chromatographed on silica gel using a gradient of 5-25% of ethyl acetate in pet ether as eluent