BENZOIC ACID, 5-METHOXY-2-METHYL-, ETHYL ESTER synthesis

Yield:855949-35-8 75%

Reaction Conditions:

Stage #1: ethyl 3-hydroxy-6-methylbenzoatewith sodium hydride in N,N-dimethyl-formamide at 20; for 3.16667 h;
Stage #2: methyl iodide in N,N-dimethyl-formamide at 20;

Steps:

1.D

Step D: Synthesis of ethyl 5-methoxy-2-methylbenzoate as an intermediate; [0097] A mixture of sodium hydride (60% in mineral oil, 1.50 g, 37.4 mmol) in N,N- dimethylformamide (50 mL) was stirred for 10 min under a nitrogen atmosphere prior to dropwise addition of ethyl 5-hydroxy-2-methylbenzoate (5.18 g, 28.7 mmol) as a solution in λ/,λf-dimethylformamide (100 mL). After this time, the mixture was allowed to stir for 3 h at room temperature before iodomethane (2.69 mL, 43.1 mmol) was added and the mixture stirred overnight at room temperature. After this time, the mixture was poured into water (200 mL) and extracted with ethyl acetate (200 mL). The organics were then washed with 5% aqueous lithium chloride (200 mL), water (200 mL) and brine (100 mL), dried over magnesium sulfate and concentrated under reduced pressure. Purification by flash chromatography (silica, 1 :19 ethyl acetate/hexanes) afforded ethyl 5-methoxy-2- methylbenzoate (4.18 g, 75%) as a clear oil: ¹H NMR (300 MHz, CDCl₃) δ 7.44 (d, J= 2.7 Hz, IH), 7.14 (d, J= 8.4 Hz, IH), 6.95 (dd, J= 2.7, 3.0, 8.4, 8.7 Hz, IH), 4.35 (q, J= 6.9, 7.2 Hz, 2H), 3.82 (s, 3H), 2.51 (s, 3H), 1.39 (t, J= 7.2 Hz, 3H).

References:

WO2009/42907,2009,A1 Location in patent:Page/Page column 35