Mechanistic Studies on Thiazolidine Formation in Aldehyde/Cysteamine Model Systems
作者:Tzou-Chi Huang、Lee-Zen Huang、Chi-Tang Ho
DOI:10.1021/jf9705633
日期:1998.1.1
A mechanism was proposed to elucidate the formation of a thiazolidine in aldehyde/cysteamine modelsystems. Buffer dramatically promotes thiazolidine formation from formaldehyde and cysteamine. Phosphate tends to stabilize the primary carbocation formed, and this may lead to completion of the cyclization by attack of the amino nitrogen on the activated carbon. Protic solvent, by removing the water
The present invention provides a process for producing bisphenol A which is capable of prolonging the life of an acid-type ion exchange resin partially modified with a sulfur-containing amine compound as catalyst, and increasing the yield of bisphenol A per unit quantity of the catalyst. There is disclosed a process for producing bisphenol A by reacting acetone with phenol in the presence of an acid-type ion exchange resin partially modified with a sulfur-containing amine compound as catalyst and alkylmercaptan as co-catalyst, said process comprising:
conducting said reaction using a multi-stage reaction apparatus comprising at least two individual reactors connected in series to each other, wherein the molar ratio of total alkylmercaptan to total acetone and the molar ratio of total acetone to phenol are increased as the conversion rate of the phenol is decreased.
本发明提供了一种生产双酚 A 的工艺,该工艺能够延长用含硫胺化合物部分改性的酸 型离子交换树脂作为催化剂的寿命,并提高单位数量催化剂的双酚 A 产量。本发明公开了一种生产双酚 A 的工艺,该工艺通过丙酮与苯酚在部分改性为含 硫胺化合物的酸性离子交换树脂作为催化剂和烷基硫醇作为助催化剂的存在下发 生反应来生产双酚 A,所述工艺包括: 1:
使用多级反应装置进行上述反应,该装置由至少两个相互串联的独立反应器组成,其中总烷基硫醇与总丙酮的摩尔比以及总丙酮与苯酚的摩尔比随着苯酚转化率的降低而增加。
Antiperspirant and deodorant compositions
申请人:The Procter & Gamble Company
公开号:US10568825B2
公开(公告)日:2020-02-25
The present application relates to antiperspirant compositions comprising perfumes and sulfur-based perfume raw materials, and methods for making and using the antiperspirant compositions.
The present application relates to perfume raw materials, perfumes, perfume delivery systems and consumer products comprising such perfume raw materials, perfumes and/or such perfume delivery systems, as well as processes for making and using such perfume raw materials, perfume delivery systems and consumer products. The perfumes disclosed herein expand the perfume communities' options.
The present application relates to fragrance compositions comprising perfume raw materials that resist fragrance habituation, and methods for making and using the fragrance compositions.