Preparation method of methocarbamol degradation derivative

The invention relates to a brand-new preparation method of a methocarbamol degradation derivative. The method comprises the following steps: 1) reacting guaiacol glyceryl ether (compound A) with triphenylchloromethane, and selectively performing primary hydroxyl protection to obtain a compound B; 2) carrying out nucleophilic substitution reaction on the compound B and dicarbonyl imidazole to generate a stable compound C, and then generating a compound D with ammonia water by a one-pot method under the condition of the same system; and 3) performing deprotection on the compound D under an acidic condition to obtain the degraded impurity E. The method avoids the use of explosive and supervising reagents, and has the advantages of easily available reaction raw materials, short steps, high yield, simple purification, less three wastes, large-scale production, low cost and the like. The requirements of the market on the standard substance of the methocarbamol degradation derivative can be met by single operation i