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| CAS号 [135-58-0] 生产工艺。 二甲基噻嗯 |
CAS号 [135-58-0] 生产工艺。 二甲基噻嗯
CAS名：Thianthrene, 2,7-dimethyl- 历史参考文献：待检索。
用途：医药。LookChem网登录生产与经营单位24家。 反应类别：杂环化。
反应式：本人有加注，产品：1. 为单一体（Mitigal）。 2. 为混合体（Sintol）。
BIOS Trip. No. 1155, 110-111. Mitigal (Dimethyldiphenyldisulfide =
2,7-dimethylthianthrene ).
(Ludwigshafen). 英国人译自德文。
本进口出版物复印件，本人未收藏。下面是以前的手工抄录文，英国人未说明资料来源。
The plant for this preparation is quite
small, but as the throughput is rapid the output is quite considerable for a
product of this type, being 4-5 tons/month.
Dr. Hopf is in charge and demonstrated the plant which was working when
inspected.
The reaction is of Friedel-Craft type between
Sulfur and Toluene. 反应式：略。
This is the main reaction but many other
by-products are formed and are separated by distillation. The rodt is not quite pure as it boils over a
range of temperature but this is an advantage in practice as it prevents crystallization
of the production. (Dimethylthianthrene has m. pt. 123℃).
The reaction vessel is a 300 l. steam
jacketed stainless steel (V2A) vessel fitted with stirrer, thermometer, gas
outlet, reflux condenser, dip pipe and compressed air connection. This is charged with toluene (180 k.), Sulfur
(79.5 k.) and anhydrous aluminium chloride (13.0 k.). The mixture is heated gently with stirring
and the temperature is raised to 114℃, slowly during 4-5 hours. The evolved H2S is let out of the building
and burned continuously at a burner fitted with a pilot jet to keep the flame
alight. No attempt is made to absorb the
sulfur dioxide produced. When evolution
of gas ceases the mixture is cooled and blown into a 400 l. enameled cast iron
vessel containing water 50 l. This
vessel is also equipped with stirring gear, gas outlet, thermometer, and steam
jacket and is connected by a vapor pipe to a condenser and receiver arranged
for vacuum distillation. The aqueous
layer is run off, the residue washed with water (50 l.) containing 33% caustic
soda (2 k.) and washing with water in 50 l. lots is repeated. The gas outlet is then closed, and the
toluene and water is distilled off in vacuum.
Vacuum is produced by a steam ejector.
About 75 k. toluene is recovered and can be used again after drying and
redistilling. The residue is blown into
a stainless steel vacuum still of 100 l. capacity. This has a short ring packed column and is
heated by electric immersion heaters, the total loading being 10 K. W. This still is also fitted with a stirrer
running at about 30 r. /m. and vacuum is also produced for this still by a
steam ejector, 5 mm. working pressure being obtained in this still. At this pressure the fraction being 190-215℃. is collected. From the above quantities a yield of 110 k. =
73% theory is obtained and a residue of about 38 k. resinous material remains
in the still. This is run out through a
bottom outlet whilst it is hot and discarded..
The product so obtained still has an
unpleasant smell belisved to be largely due to the presence of thiocresol. The material (500 k.) is placed in a 1400 l.
aluminium vessel fitted with stirring gear and jacketed. The jacket is supplied with steam at 140℃., and a large quantity of steam is blown
through the hot material to remove the odor.
The process states that 3000 k. of steam are needed, but this is not
measured in practice and the time of blowing is judged by experience. The workers consider the amount of steam used
is much less than that given in the “Vorschrift”. When the odor has been removed, the product
can be dried by stirring and heating for about 1 hour and this used to be
done. At present this has been
discontinued and the product is sold containing some water. Itt was stated by Dr. Hopf that doctors
preferred this as the Mitigal emulsified with the water, and was more easily
absorbed into the skin. This is possibly
only an excuse which enables an inferior product to be used. Owing to the well-known fact that emulsions
are usually lighter than their components, the Mitigal now being marketed,
whilst appearing light in colour, is much darker than the original product, and
the plant chemists admitted that a product of this quality could not be
produced without redistillation. The
outlet is thus doubled and the cost lowered by using wet material as only one
still is available.
BIOS 1651, 81. 本人未收藏，张澍声 《精细化工中间体及产品生产工艺》2006年。 P. 717-718. 译文如下。
二甲基噻嗯和二甲苯基硫：
Sintol T 是二甲基噻嗯（Dimethylthianthrene）和二甲苯基硫（Ditolyl sulphide）的混合物，由Elbefeld公司开发用作皮肤药剂，当时有20% 销售用作PVC和氯化橡胶的增塑剂。其制备是在三氯化铝存在下，甲苯与硫反应。反应产物洗涤除去过量甲苯，馏余物再真空蒸馏，馏出物洗涤除去甲苯硫酚（由于分解所形成）并再干燥。产品由80% 二甲基噻嗯和20% 二甲苯基硫组成。（抄注： [135-58-0] 80% + [620-94-0]
20%）。
384 kg 无水纯甲苯流入1000 L铸铁反应釜（有加热和冷却蛇管，回流冷凝器，蒸汽出口和吸收系统，人孔，氮气管线）中，随后加入128 kg研磨过的干硫黄。再加入无水三氯化铝，数量取决于要求的粘度，在28-44 kg 之间变动。高粘度28-30 kg，低粘度40-44 kg.
加热升温速度为1.5-3小时达到53℃; 3.5-7小时达到70℃；6.5-13小时达到90℃；9-17小时达到110℃。这与衬砖情况等有关。硫化氢开始缓慢释放，在内温70℃时主要反应开始，当温度达到90℃时，反应几近结束。在反应末期，在110℃保持2小时。反应完成后，通冷水冷却，约需12小时。
硫化氢在吸收系统吸收，其中有2600 kg 30% 氢氧化钠溶液进行循环。有两个吸收串联，气体先进入部分吸收的吸收器，再接触较新的试剂。吸收后的气体再通过室外的活性炭系统。当吸收了12批的硫化氢后，含有19% - 20% 硫化氢，用槽车运出处理。
冷却到45-50℃后，将4锅反应物压入一2000 L搪瓷搅拌洗涤器，洗涤粗产品，其中加有50 kg 岩盐和250 L水。搅拌0.5小时，破坏三氯化铝，静置15分钟，仔细全部放出水层。为了避免泡沫和乳化，加入一些清油。该水层通往酸性排放线。油层用碳酸钠溶（50 kg Na2CO3在250 L水中）洗涤·，该洗涤液在碱性排放线处理，以免与酸性液体混合，发生难闻的气体。
洗涤并中和过的油层用氮气压送到2000 L 甲苯回收釜（有蒸汽夹套和直接蒸汽，冷凝器和接受器，分离的甲苯经两个氯化钙干燥塔，再达到贮槽）。蒸汽夹套加热，甲苯首先蒸馏出来；大部分甲苯蒸出后，再通直接蒸汽回收甲苯。回收的甲苯与水分离，氯化钙干燥，贮存以备复用。将8批的粗品油合并，在80-85℃干燥5-8小时。开始时要小心，以避免严重的泡沫。蒸汽抽吸出来，经吸收系统吸收后放空。每批干的物料约250kg，送往蒸馏。在2700 L铸铁蒸馏釜中加入2000 kg粗物料，无需精馏，在160-170℃/4mmHg蒸馏，这一阶段需15-19小时，得到的蒸馏产品为加料量的75%-80%。前馏份数量少于加料的0.5%。馏余物为树脂状残渣，趁热抽吸到一盘中。前馏份和残渣据说可复用于Sintol T 制备，但实际上未实行。
在蒸馏中往往形成一些甲基苯硫酚，可用氢氧化钠溶液再洗涤除去。这是很必要的，因为它气味难闻，并且侵蚀皮肤。1500 kg要处理物料用230 kg 30% 氢氧化钠溶液在80℃洗涤4小时，然后通直接蒸汽升温至100℃。水层含有10%-20% 甲基苯硫酚溶液，静置，分离，收集。该产品也能再转化为Sintol T，但是气味的妨碍是很大的。第二次洗涤用115 kg 30% 氢氧化钠溶液和3000 L水，直接蒸汽加热到100℃，搅拌1小时。第二次洗涤后，再用水在100℃处理除去微量的碱。洗涤成中性的产品在100℃干燥（直接取样在0℃半小时后无浑浊），在铝制压滤机上过滤，得成品。
以加料甲苯计，收率46%；以使用甲苯计，收率71%。
回收的NaHS相当于16.8份硫。
规格：二甲基噻嗯含量至少80%；比重1.20；粘度60-80.
抄注：张澍声 《精细化工中间体及产品生产工艺》一书，是非正式出版物，所以抄录上网供读者参考！
PB 1701. Pharmaceutical and Insecticides at
I.G. Farben plants, Elberfeld, and Leverkusen.
1925-1944年 德文生产工艺。
PB 1701. Doc. 9. No. 19. Mitigal
(Dimethylthianthrene). 共36页。德文生产工艺原件。 本人未抄录。
温故而知新：
本人再次抄录上网，仅供读者参考！今天还能上网已是再大的幸福！再次谢谢读者的点读！
陈忠源 2018年12月20日星期四。
文章作者：陈忠源 |
