Disclaimer: The materials provided below are informational and should not be relied upon as legal advice.
We need more facts to understand your situation. If you are buying the house only with your own separate property assets, and you don't believe you will owe any money to your husband in the divorce proceeding, you may be able to purchase the house. You should consult your own lawyer to protect your legal rights.
Please note, that this information is general in nature and does not necessarily apply to your specific situation. This is not legal advice, nor is it intended to create an attorney-client relationship. You really should speak with an attorney so that s/he can best advice you as to your individual best interests.
There is much more information that is needed. In general, anything that you purchase after date of marriage and prior to date of separation (legal term), or with the use of community property funds (another legal term), is community property (you both have an interest in the asset). Date of separation is the date when one of you tells the other that the marriage is over. This can be done verbally or in writing. This statement puts an end to community property in the future, but does not change the community property "character" of the whatever was acquired in the past. The problem is that "date of separation" is often a hotly contested issue and often boils down to what you or your spouse (or your respective attorneys) can prove. I recently mediated a case where the couple and their attorneys had just finished three days of trial just on the issue of date of separation.
If there is a real emergency (personal safety), you should contact an attorney immediately who can file the divorce paper work and get you immediate protective orders. The courts do not consider a "great deal that might get away" as an emergency. If that is the case, odds are that you will lose out on that deal if you proceed through the court process.
That having been said, you may want to consider entering into a formal agreement (a marital agreement) as to the purchase of the property - where the funds will come from, how the property will be characterized, who will be responsible for payments, insurance, taxes, etc. You really should consult an attorney before entering into this purchase. If your goal is a peaceful resolution, I would recommend that you contact either a collaborative attorney or an attorney mediator. This process tends to be faster, cheaper, and more satisfying than contested court battles.