Sodium methyl sulfate synthesis

Yield:104-93-8 97% ，512-42-5 50.8 g

Reaction Conditions:

Stage #1:p-cresol with sodium hydroxide in ethanol at 35; for 1 h;Inert atmosphere;Cooling with ice;
Stage #2:dimethyl sulfate in cyclohexane at 40;Reflux;Solvent;

Steps:

1; 2; 1.1; 2.2 Neutralization reaction:
P-methylphenol charged in a 1000 ml four-necked flask equipped with a thermometer, a stirring paddle, a nitrogen-passing tube, and a recovery condenser:100.0g (content: 99.1%, 0.9176mol), absolute ethanol:600ml, open nitrogen protection, set nitrogen flow: 0.5l / min.The outer wall of the four-necked flask is cooled with cooling water, and the internal temperature is controlled to not exceed 35 ° C from the thermometer mouth.(Pull out the thermometer) Slowly add sodium hydroxide to the four-necked flask: 37.5 g (0.9375 mol).After the completion of the feeding, the reaction was stirred for 1.0 hour.After the reaction was completed, the outer wall of the four-necked flask was heated with hot water of 85 to 90 ° C, and the ethanol was continuously distilled off under the protection of nitrogen.At the end of distillation, the rate of ethanol outflow will be smaller and smaller.When the ethanol outflow is extremely small, vacuum recovery is performed, and the degree of vacuum is greater than -0.08 MPa to recover the ethanol, and the residue in the four-necked flask isSodium p-methylphenolate,Quantity:121.1g, content: about 98.2%.In 500ml with thermometer, stirring paddle,The prepared sodium p-methylphenol was placed in a four-necked flask of a reflux condenser:50.0 g (content: about 98.2%, 0.3777 mol), cyclohexane: 300 ml.The outer wall of the four-necked flask was insulated with warm water of 40 ° C, stirred, and the stirring speed was adjusted to be greater than 500 r/min.Weigh dimethyl sulfate: 50.0g (content: 98.7%, 0.3917mol) was added to the constant pressure dropping funnel, and then the dimethyl sulfate in the constant pressure dropping funnel was added to the four in 30-60 minutes. The methylation reaction was carried out in a mouth flask.The dimethyl sulfate is added dropwise,Keep warm for 5.0 to 8.0 hours.Post processing:After the insulation is completed, it is filtered after cooling. The filter cake was washed with 100 ml of cyclohexane, and dried to obtain sodium methyl sulfate: 50.8 g, content: 97.3%. The filtrate was washed with alkali water, and the solvent was recovered (the washed alkali water was used), and the solvent was recovered to obtain p-methylanisole: 45.6 g, content: 98.1%, yield: 97.0%.

References:

Xinchang Tai Ru Technology Co., Ltd.;Zhao Deying CN110054549, 2019, A Location in patent:Paragraph 0041-0043; 0044-0047; 0052-0058

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