Although you are in sales, you can prioritize when describing it, because you can communicate well with customers on the basis of your knowledge and familiarity with this chemical product.
Secondly: although you are engaged in sales, you have not left your line of work. This year's work experience has enabled you to accumulate an understanding of the chemical industry. When writing a resume, you can write: "In the sales work, I learned about the customer needs of the chemical industry market and had a certain understanding of the product research and development direction." Don't do research and development according to the needs of the industry. Usually, before developing and producing new products, we should investigate the whole market, instead of developing whatever we want, otherwise there will be no sales market for the developed things.
Besides, you can also write down the research and development experiments you participated in during your school days. You've only been working for more than a year, and it's not too late to change careers. If HR asks you why you quit your job, you can tell him frankly. This is your career plan. At the same time, through your previous work experience, you found yourself more interested in chemical synthesis, which strengthened your determination and confidence in chemical synthesis, and you also intend to develop in this field in the future.
In short, combine the job you want to apply for and try to connect the two.