This invention relates to a novel process for preparing unsymmetrical dithioacetals and dithioketals from aryl aldehydes and ketones comprising:
a) allowing one part by moles of a compound of the formula to react, in a suitable organic solvent, with a mixture of about 0.8 to 1.2 parts by moles of a thiol of the formula R²SH and an excess of a suitable hexaalkyldisilazane, in the presence of a suitable N-heterocycle catalyst, to form a trialkylsilylated hemithioacetal intermediate of the formula
b) allowing the trialkylsilylated hemithioacetal intermediate to react, in a suitable organic solvent, with at least about 0.8 to 1.2 parts by moles of a thiol of the formula R³SH, in the presence of a suitable Lewis acid.
本发明涉及一种从芳基醛和酮制备不对称二
硫代
乙醛和二
硫代
酮类化合物的新工艺,包括
a) 在合适的 N-杂环催化剂存在下,使 1 份(摩尔)式化合物在合适的有机溶剂中与约 0.8 至 1.2 份(摩尔)式 R²SH 的
硫醇和过量合适的六烷基二
硅氮烷的混合物反应,形成式三烷基
硅烷化
硫代
乙缩醛中间体
b) 让三烷基
硅烷基化的半
硫代
乙醛中间体在合适的有机溶剂中,与至少约 0.8 至 1.2 份(摩尔)式 R³SH 的
硫醇在合适的
路易斯酸存在下反应。