Text from Brethrick:
"The hot material remaining after vacuum stripping of solvent up to 130°C decom-posed with evolution of gas and then exploded violently 50 min after heating hadceased. Further attempts to distil the acid chloride even in small amounts at below1.3 mbar caused exothermic decomposition at 110°C. It was, however, possibleto flash-distil the chloride in special equipment . Two later similar publicationsrecommend use in solution of the unisolated material . Smaller scale distilla-tion of the chloride at 94 – 95°C/0.03 mbar had been uneventful, but a 1.2 mol scalepreparation exploded during distillation at 128°C/1.2 mbar , even in presence ofphosphorus pentachloride, previously recommended to reduce the danger of explo-sion during distillation . Many previous explosions had been reported, and theneed for adequate purity of intermediates was stressed. It is shock sensitive "