6. Unsecured Exchangeable Senior Notes

The following summarizes the unsecured exchangeable senior notes outstanding as of March 31, 2012 (dollars in thousands):


	Coupon/ Stated Rate			Effective Rate(1)			Exchange Rate			Principal Amount			First Optional Redemption Date by Company			Maturity Date
3.625% Exchangeable Senior Notes		3.625	%		4.037	%		8.5051	(2)	$	747,500			N/A		February 15, 2014
3.750% Exchangeable Senior Notes		3.750	%		3.787	%		10.0066	(3)		450,000			May 18, 2013	(4)	May 15, 2036

Total principal											1,197,500
Net unamortized discount											(2,720	)
Adjustment for the equity component allocation, net of accumulated amortization											(46,283	)

Total										$	1,148,497

(1)	Yield on issuance date including the effects of discounts on the notes but excluding the effects of the adjustment for the equity component allocation.

(2)

The initial exchange rate is 8.5051 shares per $1,000 principal amount of the notes (or an initial exchange price of approximately $117.58 per share of Boston Properties, Inc.'s common stock). In addition, the Company entered into capped call transactions with affiliates of certain of the initial purchasers, which are intended to reduce the potential dilution upon future exchange of the notes. The capped call transactions were intended to increase the effective exchange price to the Company of the notes from $117.58 to approximately $137.17 per share (subject to adjustment), representing an overall effective premium of approximately 40% over the closing price on August 13, 2008 of $97.98 per share of Boston Properties, Inc.'s common stock. The net cost of the capped call transactions was approximately $44.4 million. As of March 31, 2012, the effective exchange price was $135.14 per share.

(3)

In connection with the special distribution of $5.98 per share of Boston Properties, Inc.'s common stock declared on December 17, 2007, the exchange rate was adjusted from 9.3900 to 10.0066 shares per $1,000 principal amount of notes effective as of December 31, 2007, resulting in an exchange price of approximately $99.93 per share of Boston Properties, Inc.'s common stock.

(4)

Holders may require the Operating Partnership to repurchase the notes for cash on May 18, 2013 and May 15, 2016, 2021, 2026 and 2031 and at any time prior to their maturity upon a fundamental change, in each case at a price equal to 100% of the principal amount of the notes being repurchased plus any accrued and unpaid interest up to, but excluding, the repurchase date.

On January 10, 2012, the Company announced that holders of the 2.875% Exchangeable Senior Notes due 2037 (the "Notes") of its Operating Partnership had the right to surrender their Notes for purchase by the Operating Partnership (the "Put Right") on February 15, 2012. The opportunity to exercise the Put Right expired at 5:00 p.m., New York City time, on February 8, 2012. On January 10, 2012, the Company also announced that the Operating Partnership issued a notice of redemption to the holders of the Notes to redeem, on February 20, 2012 (the "Redemption Date"), all of the Notes outstanding on the Redemption Date. In connection with the redemption, holders of the Notes had the right to exchange their Notes prior to 5:00 p.m., New York City time, on February 16, 2012. Notes with respect to which the Put Right was not exercised (or with respect to which the Put Right was exercised and subsequently withdrawn prior to the withdrawal deadline) and that were not surrendered for exchange prior to 5:00 p.m., New York City time, on February 16, 2012, were redeemed by the Operating Partnership on the Redemption Date at a redemption price equal to 100% of the principal amount of the Notes plus accrued and unpaid interest thereon to, but excluding, the Redemption Date. Holders of an aggregate of $242,735,000 of the Notes exercised the Put Right and the Operating Partnership repurchased such Notes on February 15, 2012. On February 20, 2012, the Operating Partnership redeemed the remaining $333,459,000 of outstanding Notes at a redemption price equal to 100% of the principal amount of the Notes plus accrued and unpaid interest thereon.