During the three months ended March 31, 2022 and 2021, the Company recorded approximately $0.4 million and $0.3 million, respectively, in depreciation expense.
7. ACCRUED EXPENSES
Accrued expenses consisted of the following (in thousands):
| | | | | | |
| | March 31, | | December 31, |
| | 2022 | | 2021 |
External research and development | | $ | 37,724 | | $ | 23,282 |
Accrued professional services | | | 4,453 | | | 4,075 |
Accrued consulting | | | 721 | | | 811 |
Accrued compensation | | | 3,689 | | | 417 |
Other | | | 98 | | | 319 |
Total accrued expenses | | $ | 46,685 | | $ | 28,904 |
8. CONVERTIBLE PREFERRED STOCK
Series A Convertible Preferred Stock
On January 10, 2020, the Company entered into a Series A Preferred Stock Purchase Agreement (“Series A Purchase Agreement”), pursuant to which it could raise up to approximately $218.0 million through the issuance of up to 234,257,469 Series A shares, excluding the issuance of shares of Series A upon conversion of the October 2019 Notes, par value $0.0001 per share, for $0.9306 per share (“Series A Original Issue Price”).
During 2020, the Company sold a total of 234,257,469 shares of its Series A for gross proceeds of $218.0 million, excluding the shares of Series A issued upon conversion of the October 2019 Notes.
Series B Convertible Preferred Stock
On November 2, 2020 (the “Series B Original Issue Date”), the Company entered into a Preferred Stock Purchase Agreement, as amended on November 18, 2020 (“Series B Purchase Agreement”), pursuant to which it immediately issued 98,654,203 shares of Series B convertible preferred stock (“Series B”) (the “Series B Initial Closing”) at a purchase price of $2.7419 per share (the “Series B Original Issue Price”).
Based upon the terms of the Series B Purchase Agreement, after the Series B Initial Closing, the Company could sell, in one or more additional closings, 191,473,066 additional shares of Series B to one or more purchasers who are existing stockholders of the Company or are mutually acceptable to the Company and its board of directors, provided that (a) such subsequent closings were consummated prior to March 31, 2021, (b) each such additional purchaser became a party to the Series B transaction agreements, and (c) the Company could not sell and issue more than 191,473,066 shares in aggregate in all closings under the Series B Purchase Agreement (“Series B Additional Closings”). During the year ended December 31, 2020, the Company issued a total of 181,261,150 shares of Series B for aggregate proceeds of $497.0 million in the Series B Initial Closing and through Series B Additional Closings.
On January 28, 2021, the Company further amended the Series B Purchase Agreement to increase the number of shares of Series B that could be issued under the agreement from 191,473,066 to 207,885,043. In January and February 2021, the Company issued an additional 26,133,332 additional shares of Series B at the Series B Original Issued Price for aggregate proceeds of $71.7 million.
Conversion of Convertible Preferred Stock
Pursuant to the terms of the Merger Agreement, upon the Closing Date, each share of Legacy EQRx convertible preferred stock issued and outstanding immediately prior to the Closing Date was converted into shares of the