Synthesis Process of X-IPM, Stable Crystal Form and Application Thereof

A process for producing X-IPM of formula III, comprising the following steps:

• (1) mixing dichloromethane with 2-haloethylamine hydrohalide I, starting stirring and setting the temperature down to −70° C. to −60° C., and when the temperature is reduced to −30° C. to −20° C., adding phosphorus oxyhalide II;
• (2) adding dropwise a solution of compound M in dichloromethane in batches at a temperature range of −70° C. to −40° C.:
• {circle around (1)} for the first dropwise addition, the solution of compound M in dichloromethane comprises compound M in an amount 1.8 to 2.2 times the molar equivalent of phosphorus oxyhalide II, and the rate of the dropwise addition should ensures that the temperature change of the reaction system is within 10° C.;
• {circle around (2)} for the second dropwise addition, the solution of compound M in dichloromethane comprises compound M in an amount 0.9 to 1.1 times the molar equivalent of phosphorus oxyhalide II, and the rate of the dropwise addition should ensures that the temperature change of the reaction system is within 10° C.;
• and
• {circle around (3)} for the nth dropwise addition, the aforementioned dropwise addition step is repeated, the temperature of the system is increased by 5° C. to 15° C. with each addition, and the molar equivalent of compound M is decreased with each addition since the second dropwise addition;
• (3) after the completion of the reaction, carrying out post-treatment to obtain a product;
• wherein the n is an integer, and n≥2;
• X in the 2-haloethylamine hydrohalide I and X-IPM are identical, and both are Br or Cl;
• Z in the 2-haloethylamine hydrohalide I is Br or Cl;
• Y in the phosphorus oxyhalide II is Br or Cl;
• and
• the M is pyridine or R3N, wherein the three R groups are each independently methyl, ethyl, propyl or isopropyl.