Chloroacetyl chloride

Through the exploration of preliminary experiments, it was found that using pristine chitosan with molecular weight of 200 kDa and degree of deacetylation of 85% could obtain N,N,N-trimethyl-O-(ureidopyridinium)acetyl chitosan derivatives with high yield and degree of substitution. Chitosan (MW 200 kDa, the degree of deacetylation 85%) was purchased from Qingdao Baicheng Biochemical Corp. (China) and used without purification. The materials, including iodomethane, chloroacetyl chloride, nicotinoyl chloride hydrochloride, aniline, 2-fluoroaniline, 2-chloroaniline, and 2-bromoaniline, used in this research were purchased from the Sigma-Aldrich Chemical Corp. N-Methyl pyrrolidone (NMP), sodium azide, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), ethanol, acetone, and methylbenzene were provided by Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). All the chemical solvents and reagents were obtained from commercial sources and used as received.

Cotton linter (degree of polymerization, DP = 850) was kindly supplied by Silver Hawk Fiber Corporation (Shandong province, China). Ionic liquid, 1-ethyl-3-methylimidazolium acetate (EmimAc, ≥95%), was purchased from Shanghai Cheng Jie Chemical Co., Ltd. DiChloroacetyl chloride (Cl₂AcCl, 97%) was obtained from Alfa Aesar (A Johnson Matthey Company). Chloroacetyl chloride (ClAcCl, ≥99.0%) was purchased from Sinopharm Chemical Reagent Co., Ltd. and benzoyl chloride (≥98.0%) was purchased from Guangzhou Guanghua Chemical Factory Co., Ltd. All chemicals were analytical grade reagents and used as received without further purification.

Chitosan was provided by Qingdao Baicheng Biochemical Corp (Qingdao, China). Its degree of deacetylation is 87% and average molecular weight is 230 KDa. Acetyl chloride, chloroAcetyl chloride, ammonium thiocyanate, hydrazine hydrated, acetic anhydride, ethanol, and the other chemical reagents and solvents were all analytical grade purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) and Sigma-Aldrich (Saint Louis, MO, USA). Three crop-threatening pathogenic fungi, Stemphylium solani weber (S. solani), Alternaria porri (A. porri), and Gloeosporium theae-sinensis (G. theae-sinensis), were supplied by the Qingdao Academy of Agricultural Sciences.