Is the profit gained from purchasing goods in cash at a discount and selling them to the company on credit at their original price permissible (halal)?

The described transaction is impermissible because its reality is the supplier selling his debt owed by the company for a lesser amount, which is considered usury (riba). The Sharia (definition)-compliant solution is for you to purchase the goods yourself and benefit from the discount, then sell them to your workplace at the agreed-upon price, thereby becoming the true supplier. If this is not possible, then you are not permitted to pay the supplier in cash.