Section 6166(g)(1)(B) provides:
(g) Acceleration of payment
(i) the redemption of such stock, and the withdrawal of money and other property distributed in such redemption, shall not be treated as a distribution or withdrawal for purposes of subparagraph (A), and
(ii) for purposes of subparagraph (A), the value of the interest in the closely held business shall be considered to be such value reduced by the value of the stock redeemed.
This subparagraph shall apply only if, on or before the date prescribed by subsection (a)(3) for the payment of the first installment which becomes due after the date of the distribution (or, if earlier, on or before the day which is 1 year after the date of the distribution), there is paid an amount of the tax imposed by section 2001 not less than the amount of money and other property distributed.