Legal Question in Real Estate Law in California

Not sure exactly what you mean, but it sounds as though you'd like to get immediate payment of the full amount due you without offering any discount or other financial consideration. My first question would be, "Have you discussed this with your brother?" He might be willing to prepay the principal due you in order to avoid having to pay the interest. By the way, I assume the deal terms are in writing, and also that the documents have been recorded. Absent a voluntary deal with your brother, another possibility would be to sell your receivable to one of the firms that specializes in buying notes backed by real estate, but this would involve financial compromise as they generally drive hard bargains.