The sugar that people often eat in daily life is extracted from sugar cane, sugar beet and other plants. There are some substances in the plant kingdom that are sweeter than sucrose. Stevia, native to South America, is 200 to 300 times sweeter than sucrose; the fruit of the West African bamboo in the tropical forests of Africa is 3,000 times sweeter than sucrose; there is also a dioscorea vine in Africa whose fruit is as sweet as 90,000 times that of sucrose. However, we rarely see these substances that are thousands of times sweeter than sucrose. The substance we usually use that is sweeter than sucrose is saccharin, which is 300 to 500 times sweeter than sucrose.
From a chemical point of view, sugar and saccharin are completely unrelated. The only thing they have in common is that they all have a sweet taste. How was saccharin discovered?
In 1879, Constantin Fahlberg, a graduate student at Johns Hopkins University, was continuing his research on the synthesis of toluene derivatives. One day at lunch, he found that the bread in his hand was particularly sweet, so he analyzed a series of synthetic toluene compounds and finally discovered saccharin.
This accidental discovery opened up a path to new inventions for Faridberg. From then on, he concentrated all his energy on studying the substances extracted from coal tar. He extracted toluene from black, sticky, and smelly coal tar. After sulfonation with sulfuric acid, treatment with phosphorus pentachloride and ammonia, he oxidized it with potassium permanganate, and finally obtained a toluene through crystallization and dehydration. Very sweet white crystals. He called it "saccharin" and measured that it was 300 to 500 times sweeter than sucrose.
Faridberg immediately announced his invention and received a patent in the United States. In 1886, the chemist moved to Germany, where he established the world's first factory for refining saccharin from coal tar. Saccharin began to break into people's lives.