Don Roos’s film adaptation of Love and Other Impossible Pursuits is set to premier at the Toronto International Film Festival.

The film, based on Ayelet Waldman’s novel and staring Natalie Portman, will be one of 335 films from 64 countries that will screen at the festival, which runs from Sept. 10 through 19. Seventy-one other films will also have their world premier at the festival.

Here’s how the film is described in TIFF’s press release, which was issued last week:

“Emilia Woolf (Natalie Portman) is a Harvard law school graduate and a newlywed, having just married Jack, her high-powered New York lawyer boss (Scott Cohen). Her life takes an unexpected turn when the couple loses their newborn daughter. Emilia struggles through her grief to connect with her precocious new stepson William (Charlie Tahan), overcome a rift in her relationship with her father caused by his infidelity, and cope with the constant interferences of Jack’s angry, jealous ex-wife (Lisa Kudrow). An adaptation of an Ayelet Waldman novel, this tearful and terrific tale by writer-director Don Roos proves that even with a pursuit like love, nothing is impossible.”

Filming for the adaptation of Ayelet Waldman’s “Love and Other Impossible Pursuits” is now in full swing in New York, various blogs report.

Photos of Natalie Portman on set made it online today, courtesy of the Hollywood blog The Bad & Ugly.

Meanwhile, filming is expected tomorrow to take place at the midtown Manhattan offices of the law firm of Kramer Levin Naftalis & Frankel, reports the legal gossip blog Above the Law. Last week, the blog obtained an internal memo from the firm alerting lawyers and staff to the filming. (The firm also said Lisa Kudrow apparently is in the film too, which so far has been unreported.)

“Filming will take place primarily on Wednesday and Thursday of next week but there will be some activity as early as tomorrow,” Kramer Levin executive director Nicholas Tortorella said in the Nov. 5 memo. “They chose our space because it conveyed the image of a big, powerful, successful NYC law firm (in spite of our recent plumbing issues). The film will be released next year and the firm will be mentioned in the credits.”

The main characters in Waldman’s novel are lawyers who meet and fall in love at a Manhattan law firm.

New York City’s mayor’s office lists “Love and Other Impossible Pursuits” as one of several movies in production on its weekly “Reel Jobs” newsletter. The newsletter says shooting began Nov. 5 and will run up through Dec. 19.

Interestingly, the film apparently has its own production company established just for the movie called Impossible Pursuits, Inc. State records show it registered as a business in New York in September, and Delaware records show it incorporated in May. (What’s that all mean for the movie? Beats me.)

Following the abrupt departure of Jennifer Lopez from the adaptation of Ayelet Waldman’s “Love and Other Impossible Pursuits,” Variety reports that producers on the film cast Natalie Portman for the lead.

Other stars include Scott Cohen and Charlie Tahan. The film is written and directed by Don Roos and produced by Marc Platt. Shooting is set to begin Nov. 10.

The film’s budget, Variety suggests, is less than $15 million.

Portman, who at one time was linked to star in the adaptation of Michael Chabon’s “The Amazing Adventures of Kavalier & Clay,” will get an executive producer credit under her Handsome Charlie Films banner. David Molner, chairman of Incentive Filmed Entertainment, says Portman’s casting saved the film.

“We were left in the lurch by one actress and rescued by another,” Molner said. “It goes to show that, particularlywith independent features, nothing is more important than the talent. It’s a blessing that Natalie loved the script and now we’ve got a strong film that we can sell at [the American Film Market].”

The film adaptation of Ayelet Waldman’s “Love and Other Impossible Pursuits” has gained a co-financier, Hollywood Reporter said Tuesday.

British-based Capitol Films will co-finance and take on worldwide sales duties for the Jennifer Lopez vehicle. Capitol headed to Cannes to find buyers for the picture.

Peter Naish, Capitol Films’ co-managing director, described Don Roos’ script as “the kind of feisty yet sexy role that could have been made for Jennifer.”

For all the news and drama surrounding film adaptations of Michael Chabon’s Mysteries of Pittsburgh and Kavalier & Clay, it’s easy sometimes to forget that Ayelet Waldman could have a movie of her own hitting theaters.

Waldman’s Love and Other Impossible Pursuits was optioned by Walt Disney before it even hit bookstores. This site hasn’t reported much on it, but it’s been in the works and drawing in talent.

Don Roos, the writer and director of The Opposite of Sex and Happy Endings, is writing and possibly directing the film adaptation. Waldman confirmed that Jennifer Lopez has been cast as the main actress.

“Yup, Jlo is in, and we’ve got preliminary financing!” Waldman said via e-mail.

Lopez is prepping for the part, according to Harper’s Bazaar.

“I’m very excited,” Lopez told Entertainment Weekly in September. “[Roos]’s fantastic. When he knew I was coming [to Toronto], he actually e-mailed me. He goes, ‘How are you doing? Are you nervous?’ I was like, ‘Yeah!’ He saw the film [El Cantante] because before we decided to work together I wanted him to see it. And he was like, ‘It’s the best female performance in five years — don’t worry about it!’ I was like, ‘I love you!’ [Laughs]”

In an interview with Zulkey last year, Waldman called Roos’ screenplay “awesome.” “It’s so good – he took lots of my jokes and made them funnier,” she said. “I loved it.”