Job Openings Organic Synthesis Chemist

About the job Organic Synthesis Chemist


Major/Field: Organic Synthesis (Any area of Organic Synthesis)

Degree: Doctor (PhD)

Experience Level: Middle (must have completed at least one Post-Doc)

Publications in Organic Chemistry an added advantage

Salary: Negotiable


Details of Prospective Employer:

Prospective Employer Name:  Zhejiang Xianju Pharmaceutical Co., Ltd

Zhejiang Xianju Pharmaceutical Co., Ltd, formerly known as Xianju Pharmaceutical Factory, is the largest, most complete domestic steroid drug manufacturer, owning the reputation as the national family planning fixed-point manufacturer, national torch plan key high-tech enterprise, national guard contract, heavy credit enterprise, top 10 API export-oriented brand enterprise in China, top 100 Chinese Chemical Pharmaceutical brand, etc. The company has a registered capital of 611 million yuan, total assets of more than 3 billion yuan, covering an area of 648.65 acres, and more than 3,000 employees, among which 15% are scientists and 35% are sales personnel.

Problem statement: issues to solve in the lab

Introduction

1. The structural modification of steroid compounds generally adopts the traditional synthesis method, but the oxidation reaction of hydroxyl group, the C11 methylenation reaction, the elimination of C3 hydroxyl group and other structural modification of steroid compounds have the problems of big pollution, many by-products and high cost, so new methods should be developed to solve these problems.


Description of the issues that need attention

1. Development of environmentally-friendly oxidation reaction systems
The oxidation reaction commonly used in industrial production are Jones oxidation, PCC oxidation, Wolfowitz oxidation and hypochlorite oxidation (or in situ generated hypochlorite in original position). However, Jones oxidation and PCC oxidation generate heavy pollution and Wolfowitz oxidation needs heavy workload during post-treatment, and hypochlorite oxidation applicability is low. We need to check if we can develop a new oxidation reaction with the advantage of green, no pollution, mild reaction, the substrate wide adaptability, catalyst used can be recycled for industrial production.

2. Introduction of a Methyl Group at steroid position C11
Due to steric hindrance, methyl groups cannot be introduced by the Wittig reaction, which is the most common way to add them in. After elimination by methyl Grignard reagent, the by-products of multiple isomers will be generated, so the introduction of a methyl group at position C11 in the steroidal structure is a non-trivial issue we would like the recruited Organic Chemist to solve.

3. Selectivity of position 3 hydroxyl elimination
In addition to the target 2, 3 elimination products (approximately 80%), 3, 4 elimination by-products (approximately 20%) are obtained. None of the methods reported in the present literature can reduce the proportion of by-products.  It is difficult to improve the selectivity of elimination of 3-position hydroxyl groups and this is the third issue we would like the recruited Organic Chemist to look at.


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